Everyone in long term relationships go through sexual lulls. They can be overcome with conversation and some effort on both sides (and some fresh ideas), but if that fails you may have a problem. Losing weight is great, but sexual attraction isn't based solely on physical attraction, so don't focus on that at all.

If he is failing to meet your needs or failing to even try to do so, you have a very big relationship issue here. He has to realize that your happiness is important too. I don't think you are making a big deal about wanted to be satisfied or shown some affection. If these are the things you feel you are lacking in your relationship and he is not going to provide them, you seriously need to look at whether or not you can continue to be in a relationship like that......