I am a 19 year old college student who has been in a soon to be 4 year relationship with my partner, an also 19 year old. To me, it has been a great 4 years. But midway, between the 2nd or 3rd year, a feeling that this wasn't right started to creep up on me. I brushed it off saying that this was what real relationships were. I asked my best friend and he said that I must accept that the initial romance fades with time. But I knew all of this. To me this was common sense. What I felt was something else. I felt that everytime I told her that I loved her I was lying. I felt that I was living out of fear. I don't even know why I asked her out. I don't know if what I felt was genuine love or just infatuation. She helped me through so many moments. She pulled me out of a deep, depressive hole in my earlier teens and made me see life in a much brighter light.
She doesn't know all of this. I never told her about my episodes, but deep down I felt in debt with her. And I feel cruel. For staying for so long despite not feeling anything. I feel like trash leading her on in a relationship where I genuinely see no future. She deserves much more and has done nothing else but love me with all her heart. In return, I would either fake feelings, be somewhat dismissive or give an unsatisfying response. I'm not saying I never felt anything for her. I do, but I am aware that simply liking someone is not enough in a relationship. What I also know if that I stay, I would eventually become a 40 year old, depressed and unfulfilled adult with kids that he never wanted, living a life that he never wished. Wondering where it all went wrong. To me that would be hell. I would rather experience the pain of regret and being the "bad guy" in her story than end up in that situation.
That is why recently I promised to myself that I would live honestly. I would not live to appeal to anyones expectations ever again. I want to be free. Not in the sense of sleeping around. It is because I feel caged in this relationship. The way I view life now, and how I picture the world, myself and the future, requires me to be alone. Even if that is at the cost of breaking my loving girlfriend's heart. I don't want to be in a relationship anymore, not with her, not with anyone. I know I was selfish for leading her on. I know I was selfish for telling her this morning that this might not be right. I don't even know if I'm genuinely thinking for myself or I'm just a an avoidant teen who has been severely swayed away for reading way too many philosophy books. But I don't want to lie to her. I don't want to be in a relationship in which I will never live fully.
TL;DR I (19M) just am not into my girlfriend (19F) anymore and am no longer interested in relationships despite feeling indebted to her for pushing me through my depressive episodes 2 years ago. I'm deeply confused and unable to discern if what I truly want is my own freedom or I'm just being avoidant. What is your advice?