How to calm nerves/anxiety?

I’m 20 years old and i have an old 9 month old son. I watch him all day everyday while my boyfriend is at work. When he gets off he helps a little bit he’ll feed him once but by that time I’m so exhausted. I have to hold him while i do dishes or laundry or while i wash bottles or make his food. He never sits down to play with him he’ll just leave him in a play pen and play Xbox and i don’t like my son just sitting there alone bored and crying so i pick him up and get mad that he’s doing the bare minimum. My son is very active which i know is normal but it’s just so difficult for me, i have migraines and a heart disease and a bladder disease and lately my health has been horrible. My son doesn’t let me sit him down without screaming, he screams when i change his diaper or feed him or when I’m changing his outfit. If i shower or if I’m making him a bottle or some baby food he screams too. It takes 10 minutes just to change a diaper because he rolls and cries and hits me. I’m always on edge and frustrated.. I don’t take it out on him but i do my boyfriend sometimes. I’ll snap because he doesn’t pick up after himself or clean or wash bottles or any clothes and then I’m called crazy or a bitch or he’ll say I’m over dramatic. Its just stressful I’m always in the house and i don’t get to do anything i enjoy, i don’t even know what i enjoy anymore. What can i do to stop this? I’m on medication for my anxiety (thc pills) and it doesn’t help me at all. It’s like every little thing makes me so stressed out and i don’t want to live like this and i want to be happier for my son...