My ex invited me to her wedding. Should I go?

I don't know if I should attend my ex's wedding. We ended on good terms but still, I really did love her. We were together for 5 years and I decided to end things when we kept fighting about the same issues. Turns out after the breakup, she attended one of those social dating tours and found her fiance. She attended one just for fun and never expected to fall in love with someone at the event. So, basically, things turned out great for her and she's happier than ever. I'm still single, struggling with bills, and unhappy. I guess this is my karma. Should I go to her wedding and wish her the best? Or should I decline to save myself from the pain?