I'm sorry you're struggling-- can you try to reach out for some support? Meds in my experience have been super helpful when I have been dealing with thoughts/feelings like the ones you stated. It can be a tough process to find something that works, but I haven't generally had meds make things worse, and I have had them help, and it sounds like things are already pretty bad so maybe it's worth it to try something new?
Parenting is hard. Being a grownup and working and taking care of kids and not losing my temper sometimes when I'm frustrated-- all hard. I try to be gentle with myself, to ask for help when I need it, sometimes to make a checklist of things to do to help give me a sense of accomplishment-- even if it includes things to check off like "kids up, dressed, and off to school" and "shower." I don't know if things get easier as kids get older, but I don't think that being overwhelmed and mentally exhausted has to be your permanent state-- I think it is possible for it to get better, and I hope it can/does for you.