I’ve accidentally got attatched

I came out of a 7 year relationship in January, which completely broke me. I’ve not been with anyone since. I’ve tried dating apps etc but none of it seems to resonate with me. I (22m) live alone, having lived with my partner since 18 for uni. I was getting over my ex , almost completely (felt that way anyway) when some girl on my Snapchat asked if anyone wanted adding to a group chat. I popped up saying yeah sure why not.

The group that was popping off, everyone laughing etc, I got along with everyone. A couple of hours in, the girl that added me DM’d me saying she can’t believe how funny I am etc. I took it as a compliment, thanked her and didn’t reply much. A few hours later she dm’s me again, something trivial, this time we kept talking. I kept calling her bro etc as that’s just how I text. About half an hour in she said something along the lines of ‘you don’t have to call be bro just because I have a boyfriend’. I thought right okay good to know, whatever.

Long story short, we spent all night chatting, ended up exchanging pictures, sharing a million compliments, and agreeing that this was the start of a friendship, with strange rules, and nothing more.

We didn’t speak for about a week after that, as she was with her boyfriend all week. A week later she dm’d me again, and pretty much the same thing happened again. It has happened multiple times since. She really likes me, thinks I’m attractive, nice etc, has said if she were single she’d get with me, and eventually said she wanted to meet me to go shopping.

That plan to meet has eventually turned in to her coming to mine; which is planned in 3 weeks from now. The idea is she comes as a friend, we have a bit of fun but nothing touching each other too much, just as a fun friendship.

Given the amount of time I’ve been speaking to her, baring in mind we’ve not even FaceTimed yet, I have accidentally caught feelings. I am nervous but excited to see her in a few weeks, but now get sad every time she’s with her boyfriend and doesn’t message me etc.

This is a very strange situation to be in, I’m just hoping someone here may have some experience in this and can give me some advice?

I’d love to just meet her in a few weeks, have some fun and stay friends, but I can’t help but feel attached to this girl.