3 years. Waste of time?

I understand ptsd and depression but after 3 years of dating is it wrong of me to want to leave after he’s said I was the reason why he wanted to kill himself? He says I don’t care or try to help but I do care and I have tried to help! I’ve even asked if there was something personally I could change and I never get a response. We’ve been dating 3 years.. 3 years and he still doesn’t open up to me.. I’m 24 I don’t want to feel like I’m walking on eggshells constantly and one wrong thing and he would kill himself because of that. He was in the military and when we first started dating it was awesome! We’d go out on dates and have fun and now all he does is sit at home on the computer. He’s obviously not doing anything to better himself either. Should I feel guilty for leaving? Would you leave too? I understand “I knew what I was getting myself into”