My [19m] girlfriend [20f] and I haven’t been able to see a future together, but we’re attempting to make it work. Is this a lost cause?

So for context, we’ve been together for nearly two and a half years, and things were going swimmingly until about a year ago. After a specific event that I’d rather not disclose, I began to notice some minor strain in our relationship that eventually started building up over time. A few months ago we had a serious discussion (something she’s hesitant to do) about the state of our relationship and we both sort of agreed that whatever idealistic teenage sentiments we had about “being together forever” and whatnot just aren’t there. She suggested that we try and work on it, and I agreed because I figured I shouldn’t give up at the drop of a hat.

It’s been a few months since that talk, and I really don’t feel any different, so I’m planning on talking to her again. Honestly, I’m not sure if I want to continue with the relationship, because I’m not happy. But in thinking about it, there’s several other factors contributing to my unhappiness as well, namely that I’m unhappy with my current university and am in the process of transferring, and I’m not sure if I’m just projecting it onto our relationship. But yet again, this unhappiness was sort of there before college and whatnot.

I just feel I can’t know for sure what the right decision for me would be: neither of us are satisfied in the relationship it seems, but I don’t think she’s on the same page—I think she’s entirely set on salvaging it, whereas I feel like it may have run its course. But again, I’m so terribly unsure. I recognize that I haven’t been trying as hard as of late, but I don’t know if that’s because I’ve just been lazy, which certainly isn’t fair to her, or if it’s because of all the negative things that I’d started to notice that have put me off of continuing this relationship.

As an admittedly immature kid who can’t decide what he wants and is still grappling with so many transitions in life, I have to ask: should I try to pick up the pieces, or would doing so still just inevitably lead to our relationship shattering?