What should I do in this situation?

Hey all, I'm in a tough spot and need some advice/feedback on what to do here. Might be a little long, sorry about that lol. Will put a TLDR at the bottom.

My ex of 3 years ago hit me up about 2.5 months ago. We started talking again and I realized how much I actually missed her. I feel like I never got over her and when she hit me back up all of those feelings came back.

Flash forward to when she texted me recently, we started talking again. We started talking all day everyday for about 2 months. Talking about literally everything and anything, our day, tik-toks, sending each other songs that reminded us of each other, etc. We had made plans and out of no where she ghosted me which I thought was pretty odd considering . I gave it a couple days and reached back out and she gave me some story about how she was in a bad mental and I was like no worries, we can figure out something for the following weekend.

The following weekend arrives and Saturday comes up and she cancels again. We make plans for the next day and I think you can guess what happens next. She cancels again but says lets do something for next weekend when she doesn't feel sick. I was disappointed but said its alright, i hope you feel better and we can plan something later in the week.

This is when it becomes weird, she starts becoming distant and I ask her if everything is alright, and she says she doesn't want to argue about this and already said sorry so why cant we move on. I said that is completely fine , I don't want to argue either, i just wanted a bit of clarity. She then doesn't text me back for a day. Then once everyday for a week just texts me at like 5 PM saying Hey and then when i answer she doesn't and keeps repeating. She then just completely goes ghost for 5 days and I shoot her a text basically asking if everything is alright. She says " I don't have the emotional energy to be doing that and doesn't want the frustrations and concerns when we weren't even anything at all. " She said there was too much pressure and was sorry for leaving me hanging for the 5 days. That definitely stung but for some reason forgave her and said we can try to take it a bit and slower and try with less pressure. She hasn't answered and its been 21 days since we talked.

We still follow each other on all social media and some of her tik-toks and ig reels she likes pop up on my timeline and it was about "Going through it right now but acting like I dont care". Another one was her reposting Silver Springs by Fleetwood Mac. I'm just confused here. She's acting like she's sad but is the one who just left me in the dust.

I can not stop thinking about her and wanting to text her. All day everyday i just think about what went wrong, if i should text her, or if i shoot dm her on IG or literally anything. I'm confused as shit here because yes even though we weren't anything, all of that talking for 2 months felt like it was something just for it to be completely shut down. What do i do here? Do i move on or text her or what? Super conflicted because it was the first girl I ever had feelings for.

TLDR - My ex from 3 years ago reached out about 2.5 months back, and we started talking every day, reconnecting deeply. I realized I still had strong feelings for her. After making plans to meet up, she ghosted, canceled multiple times, and became distant. When I asked for clarity, she kind of deflected, then eventually said she didn’t have the emotional availability and felt pressured, despite me trying to go slower and be understanding. She hasn’t responded in 21 days, and now I'm here left feeling confused, led on, and stuck obsessing over what happened.