Trying to maintain that you're not a good person is what's holding you back and isn't exactly "trying." I'm really not trying to insult you, I just want you to see that you're tricking yourself.

Forgiving yourself doesn't mean you'll start acting selfishly without fear of consequence all of a sudden, it's just the realization that beating yourself up does nothing to open your eyes to better paths towards your goals.

Don't hesitate to think about all the "mistakes" you've made, but do it with actual love and as little judgment as possible, and it'll be much more apparent where your future efforts need to be.

Keep up your mindfulness and meditation, and don't tell yourself you're not good at it, no matter what. Giving up completely is the only possible failure. Every setback can be learned from. Be well.