My DIL Banned Me From My Own Son’s Birthday Party While He Backed Her Up

I (55F) paid for my son’s surprise 30th birthday party. His wife texted me: “Don’t come—family only.” At the venue, she blocked me, saying, “Get lost!” My son stood silently behind her.
Hurt, I canceled the event by calling the venue owner. Staff packed up decorations, and catering vanished, halting the party. Guests were confused. My daughter-in-law screamed that I “ruined everything.” I explained that since I wasn’t family enough to attend, I wouldn’t fund it.
My son begged me to stop, but it was too late. I told him I deserved better after 30 years as his mother, having planned every detail—his favorite foods, childhood photos—to show my love.
I later learned his wife called me “too controlling,” claiming they needed boundaries. Family members were shocked by her actions, but my son barely speaks to me now, torn between his wife and me. I feel I’ve lost him to someone who sees me as competition.
I’m unsure if canceling was an overreaction, but I couldn’t accept humiliation while funding my exclusion. Now, I’m wondering how to mend our relationship without letting people disrespect me.