M18 what should I do in this situationship?

Sorry if this is a long one but I 18m and this girl 18f have been in a very complicated situationship for like the past 5 or 6 months and we have both told each other we like each other like a month or so into the situationship thing. however she said she wasn’t ready for a relationship after a long term relationship with her ex in which she was cheated on multiple times so fair enough and we’ve been close and touchy until about a month or so when she decided to break no contact with her ex and in normal cases fair enough cos there’s no loyalty as we’re not dating and at the start of them speaking I had no problem as after they were talking I started speaking to someone and she called me a two timer etc. and since then it’s been rocky with like arguments and stuff and I’m not entirely innocent in the arguments as I’ve done petty things like turning my location off on Snapchat when she was at his house cos I just felt jealous ig. But we argued and there were also good times cos we see each other at college every day and we’re good friends and we’re very close and a lot of the time she confided in me abt her ex and what he’s done wrong now etc being with other girls even tho they were only talking but it still hurt her cos of her thinking he’d changed. It’s just now like every argument somehow turns on me and she’s really dry on messages and when I bring it up or anything it always gets turned on me. On Tuesday she went out clubbing and he was there and she said that she didn’t know until like an hour before and before this they’d not spoken to each other for a week after an argument they had but since the night out she’s been incredibly dry and I asked her what was up and she blamed it on some argument we had the week before. And today she said she wanted some because of it and I said fair enough and today she has been at his so I’m debating whether to bring her up on it cos the reason she’s dry is because something happened between them two on the night out and not that argument we had but I don’t want to cause another argument between us. And to be honest I don’t know what to do in general cos we’re very close and I don’t want to ruin that but it seems to be more harm than good. And I’m just annoyed in general cos the reason we didn’t get together is so she can recover from him and she’s just gone back to him and in fairness to her it was her first real relationship and was two years but still it’s just shit. What should I do

Tl;dr situationship