AIO for wanting to get rid of my Facebook account?

I'm 39(f) and tomorrow is my birthday. The big 40. I thought it'd be a big deal but nobody seems to see it that way. I've never been good at making friends and have had very low self-esteem in the past. I convinced myself that it was my fault and that I wasn't likeable. Everyone who once claimed they were my friend turned their backs on me when I was growing up.

I started a job 4 years ago and got hired around the same time as some great gals. We became friends and for the first time I felt understood and appreciated. Since then the gang has disbanded and moved on, but I didn't think they would completely phase out of my life afterwards. I asked multiple friends to have lunch with me this week or see the fireworks tomorrow and every single one turned me down, like it's not my birthday. I understand people are busy, but not one person this entire week? I'm not trying to be demanding but I'd hoped somebody would be there for me.

I'm considering getting rid of Facebook. Nobody ever messages me unless I message them first and I don't like posting. And I wish I was exaggerating about the not messaging me part, but I'm not. I'd be all alone if I wasn't the one reaching out to others first. I'm tired of always trying so hard because I care and then feeling alone and pathetic. Part of me feels bad for considering getting rid of my Facebook, but the other part is just heartbroken and doesn't want to talk. I cried at my job this week because I was so upset. I'm grateful the team was nice about it. Sadly it's my first week at my new job and someone else's birthday was yesterday, so nothing happened at work except one person gave me a sticky note saying happy birthday.

Part of me really doesn't want to see cheap happy birthday posts only because people got Facebook reminders. I'm not seeing the fireworks and I have no cake or presents this year. Part of me feels bad about the thought of hurting other people's feelings by going silent without an explanation, but I just don't see the point of having Facebook anymore. AIO for wanting to walk away?