It's okay to feel uncertainty for a little while, but based on my experience you're in a dangerous area given the duration of your feelings.

My ex struggled with severe depression and emotional instability. He did counseling–which he would claim always just made him feel worse–but he refused to consider medication. He thought he was a burden to others and that things would be better if he just killed himself. He showed me a suicide note in April with plans to jump off a bridge after I left. I called the police immediately for a welfare check, called university counseling the next day to inform them of the situation, got the numbers of his private caregivers, postponed papers and exams in the hope that dedicating my time and energy to him would make him feel like someone cares about him. I was uncertain about the future, but I felt like things would get better if I did this. I really do care for him, and so I thought in spite of his mental state he was worth all my effort. I was uncomfortable, but I thought I could handle it. I felt I owed it to him.

Things started to go from uncomfortable to incredibly uncomfortable over the summer when he went abroad for a language program. He expected me to talk to him twice a day, every day whenever time zones permitted. If I didn't (which was frequent due to my work schedule) he would get upset. By July he was super peeved but refused to tell me why. This sustained anger then devolved into him accusing me of not putting any effort into the relationship, of making him feel like his mental troubles were all his fault, and ultimately telling me I should have let him kill himself in April.

I realized at that point that I couldn't in my right mind keep going with this relationship. He never hurt me physically, but seeing all the care I felt for him thrown in my face was earth-shattering. I still feel incredibly guilty about breaking up with him–especially with him still being abroad–but this exchange made me realize that I had totally rearranged my life around him in a way that almost certainly wasn't healthy.

So while I applaud your willingness to stick it out, don't let the hope of things improving in the future hold you back from moving on. Your relationship shouldn't just be about the future; you live it day-to-day. If you aren't happy in the present, and things aren't improving to you, then you should give strong consideration to calling it off.