Wasted time on the wrong relationship - regret?

[Reflector]

With graduation season, I've regretted wasting time on a relationship. I finished my education and got established with a job I enjoy, but can't help but wonder how much happier I would've been had I been single. In college, I poured a lot of energy into the wrong relationship. A time when I should've focused on growth and independence, so much energy was invested in someone who would have no place in my life in the future. I realized it was that I desired a relationship, grew attached, and suffered from anxiety. A lot of my friends had found their person, so I felt pressure to find someone to be with and didn't recognize how much of a bad fit we were. Sometimes I felt I was living two lives - the one where I was doing well in my classes and with the few friends I had, and the other where I was in a bubble with this person. I wasted both their and my time by not having the strength to end it early. Multiple people tried to tell me it was a dead end relationship, but I was afraid of being alone. We met the first year of college and didn't make many friends outside of each other. It was lonely living away from home for the first time that we latched onto each other as a support system. We never lived together, but a lot of time was spent arguing for something the relationship wasn't, and it was draining. The only thing we had in common was that we went to the same school and had grown attached that the thought of ending it at the time felt scary. Although we sort of broke up by senior year, it wasn't until I moved away and met someone else that I had the strength to cut off all contact. It was hard to let go of the idea of what could be. We never had a closing conversation, but fizzled until we were no longer active in each other's lives as we had each grown indifferent. I am disappointed that my main memories from college are with that person versus with lifelong friends. I probably would've been sad had I been single, but the energy I put into the relationship could've been invested in much healthier ways, and neither of us had the opportunity to date others in college and grow independently. Sometimes I feel I owe them an apology for wasting both of our time, and we probably should've just been friends. Although I eventually moved on with my life, those are years I'll never get back. How can I forgive myself?   

[Gebidozo]

Don’t think like that.

Try to think that every relationship, even a failed one, is an experience and a lesson.

[ExpatInItaly]

3 hours ago, Reflector said:

Although I eventually moved on with my life, those are years I'll never get back.

Do you think life stops when you graduate or something? In my experience, sure, those years were fun. But it's not like there weren't even better times ahead. You're speaking as though it's all downhill after college. 

I get that you aren't happy for having stayed in a dead-end relationship, but I think you are being really hard on yourself here. Are you unhappy with where you are now in life? I would focus on the reason why you are idealizing a hypothetical past (having been single in college), as that's where I think your regret is stemming from. How do you think your life would be different today if you hadn't continued dating this person as long as you did? 

[Reflector]

No, I'm not unhappy with where I am at now. Actually much happier, but I carry guilt for wasting both my and another person's time. Had I not dated in college, I think each of us would have had a much more fulfilling college experience. Perhaps I would've studied a harder discipline or done more interesting experiences independent of them. I imagine I would've had more memories with friends and family versus immaturity in a relationship. I wish I would've just focused on self-growth in college, and I don't know why I felt like I couldn't let the relationship go back then even though I recognized it likely wasn't going to last. It wasn't fair to either of us.