OK so please talk to me as I have no one else to confide in. A bit of background, I've been with my partner for 15 years since I was 16. We have two amazing daughters together. Since the start of the pandemic my partner has become increasingly depressed, he lost all work etc and has sunk into a whole. When we first met we used to play PlayStation games together since having kids and just generally growing up I've stopped he will still play occasionally. My partner has certain kinks and has always been submissive in the bedroom, this has worked for us 
recently I've been exhausted and he's been hard to cope with as his depression often makes him nasty. The last few weeks he has been a bit happier and staying up late playing online. I felt a bit suspicious so had a look through his PlayStation messages to find he's been messaging several women acting as their 'simp' a totally new term for me! I am crushed especially as one particular player he's calling his 'Queen, said he's not worthy of her and thanked her for being her, please don't log off' etc. When I brought this up he went mad shouting and calling me a control freak. Things have since calmed down but I can't get over his affectionate language when he insists they have never voice chatted (this seems odd as the messages are practically worshipping her). We have lived like room mates for months and I just feel broken that he could be so flattering to a complete stranger. I am convinced there has been dirty voice chats but he insists he was just so impressed by her game play! I feel dragged down by his mental health and now shat on by this 
does anyone feel I'm overreacting because I feel like asking him to leave. Thanks for reading x