I haven’t consistently texted or called my best friend ever since i’ve gotten a bf and i feel horrible

I just started dating this guy back in July of last year. Everything has been great except for the fact that I can’t seem to hold a conversation with more than one person at a time.

This has always been a problem for me, even before getting into a relationship. Talking to anyone really takes out my social battery. However, I have to say that I have definitely been neglecting my best friend and I’s relationship. Recently I fucked up really bad and I know I did.

Her birthday was this January and her friends and I had come to DC to celebrate it with her the day before her actual birthday. When I got back to my boyfriend’s place (because i live in a different state and none of my friends have free parking - we’re long distance), I had stayed two days after her birthday then left to go back to school.

She had only told me two days ago when my friends and I were hanging out in a group that she was really hurt that I didn’t celebrate on her actual birthday as well. I wasn’t aware that was something she wanted to do because we had already celebrated but it makes sense, it’s her birthday.

I feel awful and during these recent months she’s been giving me really dry answers and she doesn’t talk to me the same way she used to. I really broke her trust and made her feel like she’s not worth being a friend. I love her more than she could ever know, she’s gotten me through the roughest times of my life. I feel terrible that i’ve let our friendship deteriorate like this and I want to rekindle it because she’s the coolest, funniest, and most like-minded person to me.

Any advice is welcome and i’m very open to criticism, I want to know how can I be a better friend to my best friend.