Overwhelmed with life in general

I'm a SAHM of a 4 and 5 yr old boy and girl who are Autistic (inital psych eval showed spectrum in line for the full tests) and they are horrifically defiant but it could also be my failure of parenting who knows... fiance works 40+ hrs a week and has his own struggles I don't want to burden him more than I already do he takes it all on himself and thats not on him... my kids have 2 different dads (not my fiance) and they are legit just not worth my time they refuse to work with me to help nurture the kids... My kids do not deserve me as their Mom. My fiance doesn't deserve a total trainwreck. I don't want to function just want to sleep or drink myself to sleep... I am sick of life and this world of drama and fake people I can't be truthful with for fear of offending... The psych offices here refuse to help me or my kids "We aren't equipped for your issues" always the don't care always the "You're fine you're a great mom you're just being dramatic" I am just done.