kuti, so sorry you are not enjoying spending time with your ds. Agree with others, if you are able to get out and about it will cut down on the intensity of your relationship and allow you both some "time out" - invite someone round for a coffee, go out to a toddler group, pop him in the buggy and go out for a walk - all these things help to give you time out even if you can't get away from each other!
WRT the specific things that are causing problems - throwing food: put your face close to his and say "no" in a low, firm voice. Repeat it as necessary (ad nauseum if necessary). If he is consistently doing it, end the meal early (presuming he has eaten some of it).
Getting on and off you - my ds does this (18m). It's often a sign that he is bored and doesn't know what to do next. I tend to go to his toybox and get a few things out (I don't show him, I just start "playing" with things, then leave him to it once he starts playing).
Hitting you in the face: same as the food chucking. Hold his hand gently and say "no" in a firm low voice. Then take his hand and stroke it against your cheek whilst saying "gentle" in a normal voice. You are then modelling the "correct" behaviour for him to imitate.
Throwing stuff around when things don't go his way: Normal. Just ignore him until he has finished tantrumming. Once he has calmed down, give him eye-contact, cuddles and lots of happy voice and smiles. Tantrums are not fun for kids - they don't like being out of control.
And finally - bear in mind that you will need to deal with these behaviours for some time to come! All of these things my ds was doing at 14 months; he is still doing them all. However they have decreased and he will respond to "no" etc (well most of the time).
HTH