I need relationship advice

Hi I'm a highschooler, I just transferred into a new school in the province, and met a new friend, and she confessed to me earlier this august, the only problem is that her friends tell me that she was lesbian, like REALLY lesbian, and they were shocked because her love actually felt real towards me, and I managed to make her straight.

There's a few things she hides though, she hides the fact that she has a girlfriend, and she doesn't like things about herself, she constantly overthinks and stuff and she's kinda jealous, she wants our relationship to just show up as like best friends in public.

As for me, I have a very shitty relationship past, my ex gf accused me of doing sexual stuff to her while we were both minors but in reality it was the opposite, I got insanely traumatized in those years, so I got therapy and got diagnosed with bipolar disorder, I'm afraid that my current gf will get tired of my moodswings and constant needyness and she's aware of my past and feels kinda bad for me

Today I kept chatting her even if she was drained, and I wanna give her foods and letters as an apology. Even though she says it's okay

I'll give her any food I could think of and write multiple letters to her.

I wish to marry her in the future, And I hope we last long.