Struggling with Spending Habits and Family Pressure

I have spending habits that my mum make me feel bad for. Buying things makes me happy and gives me a temporary boost or serotonin, it’s one of the only things that gets me through everyday life. I am always really depressed recently and have suicidal thoughts, buying something small like a teddy bear gets me through my day. It’s not like I spend a lot of money on things, just a couple cheap things a week/every 2 weeks and going out to eat once a week/2 weeks. My mum saw I bought something new today and tried to make me feel guilty about it yet again. It really stresses me out as it is, and I told her she’s stressing me out more but she said she won’t stop stressing me out about it until I stop spending. I don’t know what to do anymore I can’t cope. The way she sees it is I don’t work because of my problems and earn PIP, but I’m still saving the money and spending a little here and there. I just can’t cope with her stressing me out more all the time. I want to move out but can’t because of money and I can’t work. She also doesn’t know when to stop talking and doesn’t take the hint when I don’t speak back and go silent. She forces me to speak. She doesn’t understand