Also, alternating between good and bad days is normal. That will happen for a while until the good days outweigh the bad ones. It's good to be strong, but if you're having a bad day, allow yourself to break down if it's coming and process it rather than holding it back.
Sometimes I've seen people are being strong and doing DBing well and just holding their $hit together - this is really good but you also need to give yourself space to go ape$hit bananas in a private space. I did that. I had a breakdown a month ago that was bad, and it was because I was so concerned with holding the fort down, that i just put my own self-care aside. Since that breakdown, I am doing way better emotionally. Give yourself the gift of time and space and being completely emotional.