What am I dealing with here?! Something is definitely not right.

Hi all this is my first post. Hoping you can let me know if this is immature behaviour or signs of a mental illness.

I have known this 36 yr old man for 15 months, but I've probably only seen him 15 times because he is away with work a lot and because he just cuts me off and blocks me out of the blue sometimes. I don't know anyone he knows because he is from Interstate.

He has a VERY high IQ, a great sense of humour but not much common sense. Every time I saw him there was a new stupid /worrisome story about something he did in his life. He seems accident prone, immature, very unreliable and forgetful.

So I put all that down to his personality.

But some recent behaviour is making me wonder if he has bi-polar. He has a half sister who has a mental illness but I can't remember if he told me it was schizophrenia or bi-polar.

When I had known him for about 3 months, we had a really great day at a fair, that night was the first time he stayed over at my brothers house so I wanted him to sleep in a separate room. He didn't stay, left my house politely but quite abruptly. He unfriended me on Facebook on his way home without a word. I tried to call, he wouldn't answer, he wouldn't talk about anything. Just cut me off and totally blocked me. The only thing I could get out of him was that he doesn't want his future children to have such a cold mother. (!)

I thought that was pretty extreme and very way off. I'm always being told what a great mother I would be!

I just immediately started dating others and eventually, he started messaging me again like nothing had happened and still seemed keen. Then he went away to Afghanistan. He messaged every day he was there and bought me a present. When he got back he wanted to catch up but he kept cancelling on me at the last minute. He said he wasn't sleeping and that he had found out some bad news about a friend who has to go to court. He went and signed up for 6 sessions of counselling as he needed to talk to someone about it.

After a few weeks he got over the shock of that news but he was still not the same person. He kept telling me he doesn't feel like himself lately, he became a total hermit and never left his tiny studio apartment. It took insane amounts of patience to deal with him. I'd get vague two word answers, I'd have to ask the same thing three times to get a proper answer. It was like dealing with a zombie for months on end.

We were supposed to exchange Christmas presents but I got this message right when he was meant to be on his way over simply saying "I am tired and going to bed."

I was supposed to go see him interstate over xmas /nye and he sounded like he loved the idea but when I tried to ask what day I should come down it was like pulling teeth. He was putting me off, not answering, being vague, dragging it out. Finally at the last minute, a day before NYE, he told me I couldn't come because he was driving his troubled friend back with him, so no room in the car for me. The friend didn't come in the end so I think it was just an excuse he made to be alone. He messaged me right on midnight on NYE so he was still thinking of me.

Once he got back to town, again he told me he just hasn't been feeling himself lately. He said a whole heap of stuff has changed in the last few months and said "I'm not feeling as settled as normal" but that he still wants to hang out.

I had no idea what he means by not feeling himself. By this point he had had 6 sessions with a counsellor. I don't know what went on in those sessions but I asked him if he has PTSD and he gave me a very firm no.

Finally, we swap Christmas presents, then the next week we go out on a date and had a really great night. It seemed like he was getting better. We hung out again the next week and all was fine, he was quite happy to have me rub ointment into his sore neck and wanted me to stay over. I felt like finally we were in the clear and things would be back to normal again... but no.

2 days later we were chatting online and I asked him how he knew a girl he was friends with on FB. He flipped out, called me a stalker, told me it was none of my business - but then told me he's never met her.

I thought it was an extreme reaction to a simple question so I changed the topic and talked about other things for the next few days and he was chatting like normal again. Then I brought it up again and asked So how do they know each other if they've never met - again he went on about how it was none of my business, called me a stalker etc but told me they met via an online game. I changed the topic and talked about something else for the next 24 hours. The next morning I noticed he hadn't replied - and that he had unfriended me on facebook. Again! Just like he did a year ago - no word just simply unfriends after a normal conversation.

Again, he wouldn't pick up calls, he refused to talk, he just totally cut me off. I tried calling, texting, he blocked my number, he blocked me on FB. He completely shut me off and I had no idea why.

The only thing I managed to get out of him was that he was sick of my "repeated crap" about his friends. I was like what repeated crap?! He told me I was acting like a jealous highschool girl by asking about that girl. I simply asked how he knew someone, I've never bothered asking about anyone else in 15 months and I wasn't jealous at all! I texted and tried to explain that it was absolutely nothing like that at all, all I got was: "F8Ck off and leave me alone."

I couldn't believe it. It seemed like I was dealing with someone else. Just 4 days earlier he was quite happy to have me sit there and fix his sore neck and sleep with me - and he was speaking to me like this. It didn't seem like the same guy, it seemed crazy.

I left it for a month and felt happier without him in my life, but nevertheless I was still perplexed, so I asked him what did I do that was so deletable?! He said:

"I decided that I didn't want you in my life. You have a need to know why and are confusing that with a right to know why. There is a big difference. I was reconsidering that decision however it is now solid. So leave me alone."

After getting an odd and cold response like that, that's when I started to wonder if he had a mental illness. His reaction to a most minor, non-event is really quite scary and extreme.

So what do you think? Is he just an immature boy or is something not right here??!