<human>: Give me the gist of the text in a nutshell

So my gf and I have been dating for almost a year now and today was my birthday. I don't have shindigs or bday parties ever as I have this crippling fear over guests not coming ever since I was a child. But this year I decided to step out of my comfort zone and invited my gf to come have some birthday cake and minor festivities with the family.

She had a networking event during the day so we waited for her to finish that up so we could put on the candles and blow out the cake. Unfortunately she said it was getting late (around 9pm) and she said it would  not be worth coming all the way to me (~20 minute commute) and that she'd make it up another time. So I just blew out my bday candles with my parents there. I requested they not sing happy birthday because it would just be awkward.

Now normally I'd brush it off; its late, work, understandable. But a few months ago it was her bday and over 20 of her friends came to celebrate. All except her one cousin she invited and she was absolutely devastated about it.  Even though the rest of her friends came, one cousin not coming over was enough to have her crying on her bday. Considering she knows how much it hurts to not have someone important in her life come to her bday it made it an extra bummer for me when the one person I invited (who is also very important to me) couldn't make it.

I don't know am I overreacting? I mean my brochachos are going to be taking me to the beach this weekend as a more chill/party for my birthday and they're consistently reliable so that'll be nice. It's just the one time I invite anyone over for a birthday shindig and my crippling fear of no one coming actually came to fruition.
<bot>: crippling fear over no one coming to bday hence why never throw one. Invite one person (gf) she doesn't come. How bummed should I be or should I just get over it?