Ok, I know how unassuming the title is, but I guess that's exactly what I'm asking. For privacy reasons, I'm going to change the names of everyone, including myself.

To introduce myself, I'll go by the name Allen. I'm a sophomore in high school, and I'm a bisexual trans guy. 

So, the story all starts in the eighth grade. I'd gotten my first "girlfriend", who I'll call Molly. I say "girlfriend" because it wasn't an actual relationship; we'd held hands twice and went on only one date over a five month period. Nonetheless, at that point id considered it a real relationship and thought I was truly in love. 
This portion of my life was probably the lowest I'd ever been. My mental health was at an all time bad and my coping mechanisms were much less than healthy. To make matters worse, Molly was very manipulative. She pretty much followed the textbook of gaslighting. I'd pushed away everyone in my life except Molly, and thank God I've now repaired most of those relationships by now, but things could have gone south quickly.
Overall, a real bad experience that I'm still slightly messed up over.

Earlier this year, my good friend who I'll call Sam asked me out. I said yes and I had a datemate. Pretty quickly, though, things went sour quickly. There were lots of parallels to the situation with Molly. Things were moving too fast and I quickly found myself on an emotionally sinking ship. I was spiralling back into a shitty state of mental  health. I broke up with them after about a month because I figured I wasn't ready for a relationship.
Now, Sam is someone who I consider family. I love them dearly and would go to the ends of the Earth to make sure they were happy. Part of the reason I ended the relationship was also the fact that we are in a small club that I cherish deeply. I could attribute the people in it to saving my life on multiple occasions.

And that's where my problem lies.

Recently, I reconnected with an old friend who I'll refer to as Gwen. We hung out and hit it off quite quickly, and two days after out first hang out Gwen had asked me out. And I said yes.
Gwen is taking things much slower, as she knows my prior situations. We've got a first date planned, that's honestly more of a trial to see what the both of us are comfortable with.

And I feel like an asshole.

I'm fully aware Sam still has feelings for me, and I really don't want to hurt them. I care about them a lot, but I think I could really be happy with Gwen and I could make Gwen happy too. I don't intend on abandoning Sam, and they are still a big part of my chosen family.


So, Reddit, am I an asshole?