Is there any hlp for the mom of a clingy toddler?

My son is 16 mths old and can't stand it if I leave him alone to play while I clean or smoke a cigarette or make a phone call or even go to the BATHROOM!!!! He screams if I put him down and leave the room or if I shut the door to go potty. He has stranger anxiety evn with his own DAD sometimes. I am @ my wits end. He cries constantly and it's not like sad crying it's ear piercing SCREAMING @ the top of his lungs if I put him down and walk away or shut a door. I'm the custodial parent and he hardly ever sees his father especially since we moved 4.5 hrs away. He's been fussy and clingy since he was 5 mths old and moving didn't really affect him but he's still clingy and fussy. I'm looking for a job an I KNOW childcare is out of the question since I can't handle him let alone some stranger that doesn't evn know him. I can't evn sit in my room to watch tv without him whining sometimes and when I bring him in the room he whines because he wants out. I have been with him 24/7 since he was born and I am exhausted by the end of the day from holding him and trying to carry him and get housework done. I am completely out of ideas an have read every parenting guide I cld get my hands on but none of them have helped.....