(((Hugs)))), Martina. I feel your pain! I have gone through the whole should I give him more milk (well he's on formula because he has had a little trouble digesting cow's milk at the moment) to compensate. I too tried cutting back so that he'd eat more solids and it has helped a little bit, but not always. It doesn't help with what he will actually try. He eats the same foods almost every day and it has driven me nuts.
I was so ecstatic over the weekend because he tried a few new things and liked them. And he actually picked up some pieces of fruit and put them in his mouth. He spit them right out, but I was happy that he even tried it. Come Monday, however, the foods that he tried over the weekend and liked, were disgusting to him LOL.
I have noticed that he is more willing to try new things when we are out to eat. So I told DH we need to start eating out like 3 meals a day LOL. I think it is because he is more distracted and will just pick things up and put them in his mouth and isn't really paying attention.
I'm not much help because I haven't made much progress on the pickiness, but I will tell you that there will come a point that you will just say whatever and not stress about it. I got to that point about 2 weeks ago when DS decided that the ONLY thing he would eat was cheese. He would hold out, throw his food, and yell until I gave it to him. He got over it in a few days, but at that point I decided there is nothing I can do but offer him healthy options. (And I thought I was very close to losing my mind!) I never thought I would stop stressing about what he eats, but I did (more or less). I've told the doctor what he eats and he doesn't seem concerned, so I am trying not to be.
Sarah - I am guilty of making a few things at mealtimes too- just to make sure there is something that he likes. My ped told me absolutely not to do that (as well as not to offer a few different purees if he's rejected one he usually likes), but I still do. I've gotten better with not offering him a different puree if he rejects one, but I do still put quite a few different things on his tray and cross my fingers..