Alot of this sounds very normal for 3, sorry if that doesn't help
As so often though it is all about expectations, and understanding child development, imo. He is three, therefore very very normal for him to be "like he's some jealous lover who wants me all to himself. He will not play on his own, will not stay in a room on his own, and has always been like that". I know no 3 year olds of my acquaintance who would, or who happily share their mother's attention
With a child like this I think it is about not expecting to have adult conversations necessarily, when people come round. Or being able to get much clearing up done. Some kids just need more input, more attention and more 'policing' than others...
Your comment "I wanted a son who could look after himself, stand up and be himself" is SO sad. You are expecting WAY too much. He is 3! So sad that he is seen as a disappointment like that at this stage. And I can see that he is very hard work, of course but that comment I think is really sad for him.
The throwing of stuff is again completely normal, I am not saying it's easy to deal with but it is simply a case of being consistent, agree that stickers are a good idea because it is about looking for the positive.
Again, I've heard so often that kids can be fine when out or at other's houses, but in the home environment it's much, much harder for them - hard to share their turf, their patch, their toys etc.