Would it be a bad idea for me [19M] to reach out and apologize to the person I can best describe as the “right person, wrong time” [19NB] after 2 years?

Apologies for such a long post but there’s no way to make this long story short.

I [19M] have been in love with this person [19NB] since the summer before high school. We were pretty close through late elementary and early middle school but then they started going to a different school and we grew apart. Then, the summer before we started high school, we were reunited by chance and learned we’d be going to the same school in the fall.

Anyways, as we spent more time together in high school, we grew closer and closer to the point half the school assumed we were dating. We were incredibly physical and flirtatious and even though it was an open secret that we were both in love with each other, our respective home lives and mental health meant making things “official” would be dangerous, even if that label wouldn’t actually change much.

They lived in an incredibly abusive home and we were both in and out of residential mental health treatments so contact outside of school could be shaky. Often one of us would disappear for days and one would have no way of knowing if the other were grounded, hospitalized, or dead. This obviously takes a toll on a relationship and we ended up becoming more and more codependent when we were together until one day, things go silent on their end. It’s like that for weeks whereas other times it had only been days. Nobody knew what happened so naturally, I assumed the worst. I genuinely believed them to be dead for at least two weeks before I learned from their cousin that they had their phone taken and were sent overseas to live with their relatives.

I was crushed. Obviously I was extremely thankful that they were alive and relatively safe, but having no way to contact them and not knowing if I’d ever see them again still broke me. The next month or so was possibly the worst of my life. After a few weeks, I got a message from them on Instagram, saying they were safe and they missed and loved me. I was overjoyed but I couldn’t respond; I couldn’t even open the message.

I know how shitty this was of me and I feel guilt for it every single day but I was 16 and scared shitless and didn’t know how to handle it. They continued to text me when they could and I never responded. I read every single text and every time I wanted to respond more than anything but I just couldn’t. At first it was fear but then it was just the guilt stopping me. After a year or so they stopped trying.

It’s been 2.5 years since the day I last saw them and I’m still in love with them and think about them daily. I want to reach back out, not even to get together, just to apologize and give us both some closure but I don’t know if it’s a good idea. Part of me thinks it’s probably selfish and that’s probably the smart part but there’s another, stronger, part of me that feels like they could use this too. However, the absolute last thing I want to do is cause them any more harm than my silence has already caused. Would apologizing most likely be helpful or harmful?

TL;DR
My best friend and I were in love then they got shipped across the ocean and I ghosted them but I’m still in love with them 2+ years later. Would my reaching out to apologize cause more harm than good?