I'm not the right friend for this man but he has no one

Im married and have a family but two years ago I became friends with my daughter's teacher . Sounds terrible but believe it or not , he has shut out everyone from his personal World . We found that we had a similar interest in art and this is where our friendship began . However things took a nasty turn when he start to have periods of anger and retaliation against me. I couldn't end the friendship . I really liked him and cared for his wellbeing and happiness . Life has been really traumatic for him . Being diagnosed with bipolar which eventually destroyed his short first marriage; being a primary school teacher and knowing he will never have children of his own;losing his father and being an ocean away from him; earning enough money to pay the rent and bills; not eating right ;not sleeping well;knowing that his condition affects his skills to be a good person . His peers at school have no knowledge of his condition , at his request, and I know that they view his untidyiness and disorganisation and struggle to get things done on time as poor teacher skills .. it's a predominantly woman's career so you can imagine the staff room chatter .. not their fault though .. they don't know ..

We meet for coffee often and I know I am the only person he opens uP to.

He has never let anyone into his personal life and I really feel sad knowing this man struggles daily . 2018 was a good year though .. he has been given the right mix of medication and his struggles seemed to dissipate . However .. since this new year began .. he has completely shut me out . No return calls , no reply so to texts , declined coffees and I'm too scared to visit him for fear of making him angrier . It's school holidays and he has done nothing but stay indoors . I worry that he has stopped his meds. My hands are tied and I don't want to overstep the boundaries he has set .

If he knew I was asking for someone to help him , he would be mortified and I fear the repercussions. As a man trying to live independently with his condition he is trying so hard to manage . I'm scared . I'm scared he is doing harm to himself . I'm scared that he is depressed and distraught.

Is there anyone professional out there who can pop in to his home and just say hi ? Without him knowing that I've reached out ?

The anniversary of his father's death is late January and iknow he tortures himself mentally about it.

I'm personally struggling too .. I suffer anxiety attacks and need to focus on my family . But I just can't stop worrying about him and I would collapse if something sinister happened and I didn't do anything about it . I've not spoken to a single soul about this ... No one would understand why ... Bi polar is unfair ..

I need advice ..