I (21F) think I'm in love with my best friend (21F). I think I'm going to tell her

We met literally the first week of college. I went up to her because I thought she was cute and I was an out lesbian for the first time in my life, but she said she was straight and I figured that was that and we became best friends instead. We went out together, studied together, we could talk for hours about anything.

Sophomore year during the pandemic, my mental health basically collapsed in on itself in the worst possible way. I was living with 4 roommates I didn't know well, and felt so alone and barely real most of the time. But still, I walked the 20 minute walk to her place almost every day to lie in her bed and talk, or do work, or watch movies. For a while, she was the only person I felt comfortable reaching out to to hang out, and vice versa. We made a google document for all the different couples costume ideas we had for Halloween 2021 that we could do together. During this time, she also told me she had realized she was bisexual, and I repressed the realization that my feelings toward her were probably less than platonic. I started therapy.

Our junior year, we moved in together along with another roommate who's a mutual friend (21M), and the three of us got really close. As for the two of us, it started to feel like she and I spent all of our free time together. After we were done with classes and work, we would grab some beers and sit on the couch and watch a show or a movie (sometimes multiple movies), with a special point to watch lesbian movies since she hasn't seen so many. In every show or movie without fail one of us will point to a couple and joke about how alike they are to the two of us. I quietly realized that my feelings weren't going away, but the situation was so complicated with her being only just newly out, and my mental health still being rough. I started using dating apps more seriously, and began seeing other girls pretty regularly, though rarely getting past the first or second date.

Then spring of junior year and the summer afterward, a few things changed. She went abroad, and I started to get better. I started antidepressants, I joined a play, I started to learn guitar, I made new friends and became closer with old ones. I was comfortable being alone with my thoughts for the first time since 2019. I kept going on dates, and they still never went past date 3 or 4, but they became more fun than stressful.

The only thing wrong was that I missed her constantly, in a way that was impossible to ignore or repress. We texted constantly despite the time difference, and she would call me drunk from the club to tell her she missed me. It became a tradition to text each other about how much we missed each other whenever we got drunk. She made jokes that when I do get a girlfriend, I'll have to make sure she knows that I'll still have to spend all my time with my best friend.

Senior year starts in a few weeks, and we're moving back into the same place for the first time in 6 months, and I don't know if she likes me back, and even if she does, I don't know if she'd want to do anything about it. It's all still so complicated. Neither of us have ever been in a relationship, and it would be so serious right off the bat. We live together, and we're graduating at the end of this year.

I don't know. Typing it out feels so surreal I can't believe this is a real situation and not something out of a bad fanfiction.

I think I have to tell her, though. I'm in a good enough place where I think I could deal with a rejection, and our friendship should be strong enough by now to not fall apart if she rejects me, right? And if it turns out well...it could be really amazing.