Why is this happening

Hello, I'm new to these forums. I suffer from borderline personality disorder and severe OCD with major genetic depression. NOT LOOKING FOR RELATIONSHIP ADVICE. ASKING HOW MY MENTAL ILLNESS MAY BE AFFECTING AND FUELING THESE THOUGHTS/SITUATIONS AND REQUESTING COPING TACTICS. I'll get to the point. I have this amazing boyfriend. I don't want to leave him. I'm happy around him. Everything changed a couple weeks ago though. I haven't seen him in 5 weeks since lockdown. The last 2 week's everything he does or says just peeves me off to the extent I just want to escape him. It can be the smallest of things that I shouldn't get upset over. I missed his company just 2 weeks ago and now I've flipped to this? Why is this happening to me? Is it my mental disorders? Do I discourage it with self talk? Help please. I'm not doing really well. I lost my pet 3 weeks ago also and it broke me to pieces. I'm depressed still and trapped at home. TL;DR.... ASKING HOW MY MENTAL ILLNESS MAY BE AFFECTING AND FUELING THESE THOUGHTS/SITUATIONS AND REQUESTING COPING TACTICS. everything my bf does annoys me immensely. I have OCD,bpd,depression and anxiety. Are my mental illness the cause of my rapid changing opinions/moods towards him?