How do I be a better mummy ?

How do I be a better mummy? I give her so many things already and I do spend time with her but I don't spend as much as I would like. She's bossy and strong willed and I find I get cross with her because everything has to be her way or no way so it's not enjoyable. I don't know how I'm supposed to over come that.
I'm a stressed out mess. Seperate from DV and have been dealing with major stress from that for a year and a half now. He still is trying to control things even now. I've come a long way so far but I know I've still got a long way to go. I'm constantly stressed about things he says taking our daughter, not signing to sell a house, threats to my parents, so many things. I try to ignore him and move on but I'm constantly stressed and on edge waiting for his next blow. It seems like it's one thing or another. Works being unfair offered me part time and all was good and they changed their minds and said that's not possible anymore I need to return full time or resign. Im struggling financially and life just seems to be throwing me blow after blow. Everywhere I turn for help a door seems to get slammed in my face. Im trying to stay positive but nothing seems to be going right. Im just met with deadends and heartache. This is making me a mum I don't want to be. I've gained wait and am so down about it. I want to be that fun healthy mum again. I lost 30 kilos and was so happy and healthy and had so much fun with my daughter. Since separating I've gained that wait and struggle to get off the couch. Yes I go outs die with her and do things but I'm not that happy fun person all the time anymore. I can't afford a gym membership, she doesn't fit in my pram anymore she's 22 kilos. I've tried a scooter of a bike but I just walk it's not fun. I miss running. I used to run and push myself and try to best my time before.
I'm lost. I'm stuck in a rut I can't seem to get myself out of. I'm lost I'm stuck and I want to be a better mummy. I want to be a present mummy. A mummy that's there. It's just me and her 25/7.