I was still bfing at that age too and neither would entertain cows milk until they'd stopped bfing. Just figured that was normal, I don't really like the taste of milk that much and if you are given that instead of your favourite drink and mummy cuddles, I'd refuse it too! 
Don't think the fact that he's not eating much is a worry but the fact that it is so limited, he could do with changing that a bit.
I'd stop offering his favourites and just offer what you eat, assuming of course that you eat fairly healthily
.
Ignore the tantrums and if he doesn't eat it, wait until you have finished and then clear away. Do you eat with him now? I would really recommend eating with him if you don't.
Mine are a bit older but by that age were more or less eating what we ate. Today we are having whatever they want for breakfast, sandwiches for lunch and homemade crispy chicken fajitas for tea cos I'm too tight to buy the kits
. Tomorrow we are having breakfast, pasta for lunch and Roast Pork Dinner.
At the moment I'm trying to get them to snack on fruit between meals, which they do like but then I love fruit too.
Whatever you do, if he refuses the food you offer, never, ever, ever offer an alternative. He is getting lots of lovely nutrition from you and the food is only complimentary. If he refuses it he won't starve
.
You might like this book and Nutrition for Breastfeeding Toddlers.