Still struggling after toxic break up

I spent years being burned out in life by my narcissistic ex-fiance. We have 2 kids together and I've always been the only main parent they have, even more so once I kicked him out. Ive now been single for 3 years, but I feel so unworthy of love and although I know I deserve better than I've dealt with, I still stay clear of receiving anything. I'm a single mum, my anxiety and depression literally stop me from getting my license, finding work, etc. I know what I should do to make life better but it's so hard to take that step and; just feel useless in life, except when it comes to being a mum. I know I need change but I'm struggling so much.