Is it because they seem to have it all? I think we've discussed this before and it's always good to be able to put on a happy face at social gatherings .. Are you having a difficult time dating? Are you with somebody else? If not maybe that's the problem get yourself out there.

I've been in a 5 year long relationship, that I just ended...it had been clear to me for a long time that I have a lot of healing to do before I can be in a healthy relationship ... I don't honestly know why I let them effect me so much... they do appear happy... and I know it's stupid but their happiness feels like it's a slap in my face...and because I know it seems Stupid after all these years, I can't share these feelings with anyone...ugh just frustrated with myself and my inability to let it go

May I ask how your relationship ended with the ex you just saw at the gathering?

Don't be so hard on yourself . You are hurt for one reason or another. Sounds like you need to be alone for a while and d some soul searching. Ive learned a few things in life that no one and I mean no one is as happy as they seem because nobodies life is perfect.
i mentioned soul searching because after the relationship with the guy at the gathering you said you had been with someone for 5 years.
Did you have children with the guy at the family gathering? If so then I can say its always kind'a emotional when we see our ex that we've ad children with especially if they are still with the same person they landed up with after us.

we were together for 16 years... he left me for the ow... I was blindsided...

and yes... we have 2 daughters... and thank you for understanding... I seriously feel so stuck... just wish I could get past this and fully accept what is...

I personally think you are just NORMAL :)

Five years is a long realtionship, whether you chose to end it or not. Maybe you still have healing to do with the relationship you just ended and you are transferring those emotions to your ex. Either way, I think it is healthy to investigate those feelings and the why of them.

I personally think we lie to ourselves so much!! (Give happiness to relationships that were or ARE not, give perfection to people who are not, down ourselves for every little flaw) If we would just honestly break down our feelings and examine them, we would find much ado about nothing. Though, I know in that moment for you, that was impossible.

Bottom line, you will always have some feelings for your ex of 16 YEARS: he fathered your children. There may be a turn down knob but there is no OFF knob. And your new singleness may have flipped that knob. Maybe.

Best of luck!

There is nothing wrong with you.
Sometimes you don't HAVE to forgive people.
I just avoid being around my ex as much as possible because I still end up crying after.
Can you avoid him? He traumatized you.
It is like saying : " just get over the trauma from rape". It is not the same thing, but it is trauma. It is real.
Hugs