Not sure if this is the right place and i hope someone recognises my situaution and can help me out plssss I am at wits end and i have no more tatctics i can try with this whole thing...

My DS is 3 and a half yrs old and is the youngest of my three boys, My eldest two live with their dad and i currently dont have any contact with them due to their father and his ways.. (long story).. But my son has met them and they only recently lost contact..

My ds is wayyy out of control i mean to the point now i cant do anything at all no shopping, no visiting, no dinners, no visitors neither... Like I mean we cant even have visitors without him causing a scene...

If i take him shopping im constantly running after him, trying to get him to settle down and behave, he screams and causes a scene, chucks tantrums and everyone JUST STARES!!! which is even more frustrating...
At dinners he runs around the restaurants, throws himself on the floor and yells just a total nightmare... I am currently pregnant and its stressing me out completely and from chasing him constantly i am usually suffering from abdominal pain by the time its time to sleep... Im scared that i wil go into premature labour because of all of this..

At home he isnt settled neither, he climbs everything jumps over our railings on our stairs climbs up on the benches, jumps all over the lounges doesnt listen to a word i say he knows how to push me past the point that im over angry.. I dont hit him i dont think it would make a difference my mum says to give him a good belting but she hits him (without my permission) and it doesnt seem to help neither i dont wanna make it worse...

When at my inlaws my son is the only boy in his age bracket and is surrounded by girls and my son is the one who is blamed for the girls being hurt but i dont settle and let everyone see its all even not just my son... he loves going there but wont behave and now i have to show him if he doesnt behave we will leave... pffft he tthinks its a joke....

he talks in this baby voice and carries on and will repeat the words mum and dad continuously till you wanna scream, he takes over the tv and the only way you can get him to stop and settle you have to put a show on for him or its crazy...

I have cut out all sugar out of his diet and i only give him sweets on special occasions, I cook him almost three meals a day..

sorry for dragging on but pls if you know of anything plssss help me