Struggling with a Difficult Friendship Decision

I am going through something very difficult right now and my mind is not sure what to think or do. basically I decided not to go to my best friends second wedding a few weeks ago because my mental health is very fragile. I have a lot of things going on in my life now and it's been super hard for me to make that decision. I originally said I would only go to the ceremony but then I had a phone conversation with her one night and she just sat there in silence when I was breaking down. I had already self harmed prior to the call and when she just sat there not saying anything it made me feel like killing myself. I had called another friend after and it helped a lot. I then told my friend the other week that was how I felt(I have really been trying to be honest about my feelings ) and apparently that was cruel and not necessary for me to say. But honestly that was how I felt and I told her the next day I wasn't going to the wedding at all. Now she's blaming me for being a bad friend and saying that it's not her job to comfort me when it was my choice I made not to go. But it was such a hard decision and last night I was hit with such a big depression wave and urges to self harm were so strong. I haven't cut in a few weeks which is big because I was doing it at least 3 times a week before. and now this morning I relapsed. ugh.