Hi my ds has just turned one and I know exactly how you feel. Mine just wants to get upto mischief or dangerous activities from the moment he gets up until he goes to bed, and screams the place down if I don't let him and is generally whiney. It is very very tiring when it goes on all day.
The only way I seem to make it better is to give him my full attention every 10 minutes or so, regardless of what I'm doing. It may just be a quick game of peek-a-boo or a tickle fight, but this seems to keep him ticking over and cuts down the whinging.
For the temper tantrums or when it just gets to much I just lay him down in a safe place and ignore him or leave the room, that usually brings him round. Others say distraction works, but that only seems to work for my ds while I'm doing it and as soon as I stop he starts again.
I've found ds has been alot worse this last fortnight or so and I'm not sure if it's teething or another growth spurt time and their tired.
Please don't beat yourself up about how you've been feeling, I too have screamed at ds and then burst into tears out of sheer frustration, and then spent days worrying I've damaged him for life! I also mutter fuck off sometimes at him under my breath so you're not alone.
I just keep repeating the mumsnet mantra 'it's only a phase' which is true even though it seems to be one whingey phase after another at the moment.
Do you get out the house with him often as I find that really helps to distract them and keep them happy and at worst it makes the day go abit quicker.
Sorry for the long post, it's just I'm going through the exact same thing