Honeybun...been there, done it. It is super stressfull and I have found it hard to chill out about but I just want to give you some encouragement. I decided to offer things DS likes (on a little compartment plate) and new things he hasn't tried. Don't replenish the things he likes just give him enough. DS went through weeks and weeks of almost exactly what you describe. He's now 22 months and around 6 weeks ago I gave him one of the meals he used to love (he had gone off all hot proper food) and I was expecting it to go in the bin after 20 mins..to my suprise he picked up the spoon and hate the whole thing

. There was no rhyme or reason to why

He just did it and has continued to do it regularly, but still has off days when he will eat hardly anything. He was one of those babies I felt smug about

eating all day and anything and everything then BAM!!! Take that Mother

. He used to love cheese and then totally refused it for 5 months! 2 weeks ago he saw cheese on a pizza box and said 'Mammy Cheese!!!' I said 'Yeah whatever

' and gave him a very small piece of mature cheddar..he ate it and asked for more

and has been asking every day since.
Honey these are just 2 examples of what can happen. Try not to stress, I know for sure they pick up on it very well. Leave him alone to eat and don' even comment! it just pee's them off

. Even telling Sam 'Well done' could result in food on the floor for goodness sake

One thing that has really helped me is to put Sam on Abidec multivitamin with Omega 3. I know that every day whatever is lacking in his diet he gets from just a few drops of Abidec. It ensures he is doing well developmentally and takes the pressure off.
BIG HUGS Honey.
Vicki.x.