I don't what to do about this girl?

To cut a long story short it started at uni last year. It was the end of the final year and I pretty much fell for her the first time I saw her at the library and it must have been really obvious. At first she ignored me, then she started showing interest and we got talking and then ended up talking a lot on messenger often with her writing first and being very flirty. By that time I had fallen for her very hard. We are both in greater London and were supposed to be meeting up, so when uni finished at the end of May I messaged her but she didn't respond. I didn't hear from her until two days ago. As a result of this my summer was ruined, I pretty much went out of my mind and hit rock bottom and assumed I had been ghosted. People kept asking me if I was okay but I haven't told anybody about this embarrassing situation. I was recently feeling better and thinking about asking a different girl out. It is as if she can read my mind, because that was when she wrote to me again and it was like this wave of relief, I was on cloud nine all day, and she was being friendly and flirty again but gave no explanation as to why I was ignored, just saying she had been busy. She seems to have total control over me but now I feel completely out of my depth as I haven't had a proper girlfriend before and I don't know what to do.

To cut a long story short it started at uni last year. It was the end of the final year and I pretty much fell for her the first time I saw her at the library and it must have been really obvious. At first she ignored me, then she started showing interest and we got talking and then ended up talking a lot on messenger often with her writing first and being very flirty. By that time I had fallen for her very hard. We are both in greater London and were supposed to be meeting up, so when uni finished at the end of May I messaged her but she didn't respond. I didn't hear from her until two days ago. As a result of this my summer was ruined, I pretty much went out of my mind and hit rock bottom and assumed I had been ghosted. People kept asking me if I was okay but I haven't told anybody about this embarrassing situation. I was recently feeling better and thinking about asking a different girl out. It is as if she can read my mind, because that was when she wrote to me again and it was like this wave of relief, I was on cloud nine all day, and she was being friendly and flirty again but gave no explanation as to why I was ignored, just saying she had been busy. She seems to have total control over me but now I feel completely out of my depth as I haven't had a proper girlfriend before and I don't know what to do.