My son told me we ruined his wedding

My son(27) got married 3 weeks ago. I have another son who is 18 who was gonna be his DJ at him and his wife's wedding. Some backstory. There has been some tension in the family. When my son was 24, him and his fiancè wanted to buy a house and asked me to co-sign on a loan. I did and everything was fine for about a year until they stopped paying their mortgage. Because of that I got stuck paying their mortgage and my son will randomly ghost us and usually will come back when he needs something. He still hasn't been paying his mortgage so I've been doing that. He's also stolen and stolen from my 18 year. There's been a lot of tension but he's my son and I love him. My 18 year old asked him to try to have the wedding when it doesn't affect his football if he wants him to DJ . My 18 year old used to play but quit because of mental health reasons but now does a type of management thing on the team where he sets stuff up, gets things ready for the games and packs equipment. Well my 27 year old had the wedding date on senior night and while my son doesn't play he was gonna be recognized as an honorable team member. He was gonna skip it BUT what happened was I guess he saw me crying because I was so stressed out with bills and he told my 27 year old that he needs to treat me better and start paying his mortgage or he won't even be at the wedding. I'm still paying the mortgage and a me and my oldest had a fight and he called me a bitch because I couldn't pay for something for the wedding and my son told him he won't be at the wedding. He went to senior night and got his award. My 27 year old thought my 18 year old was bluffing when he said he wouldn't be there so him and his wife didn't arrange new DJ arrangements. So I get yelled at during the reception for not forcing my 18 year old to be there and my 27 year old told me we ruined his wedding. So now I feel like shit and that my family is falling apart.

*Forgot to add, he messaged my 18 yearbold the following day saying "congrats on your little participation award considering you didn't play all season" with a middle finger emoji. That's how things have been.

Edit: I'm not trying to enable him. Since I co-signed for their house I have to pay the mortgage if they don't or else it reflects on my credit. I also can't just sell the house since hes the borrower. From what I've been told when I asked for advice the most i may be able to do is sue my own child since he had the money to pay his mortgage he's just choosing not to