In all likelihood, he probably does still love and want you, but that is a separate issue from what is going on with him. If I had to guess, he is probably stressed about this big commitment, and not sure how to communicate his mixed feelings with you.
From the tone of your question, it sounds like you are feeling a little "poor me", which is OK...but if you are displaying this to your boyfriend with a little guilt mixed in ("why don't you love me anymore" type questions), then he won't feel he can communicate his complex and mixed feelings with you. He'll be trying to save your feelings so you don't feel even more sad for yourself. Please know that his withdrawing from sex is a symptom of something: he needs to feel secure and have space to be OK with his feelings. Relationships are going to have mixed-up feelings (not always lovey-dovey, but sometimes questioning...which is all good).
Does this all make sense? What are your thoughts? Have you asked your boyfriend how he is feeling about moving in...what that entails as far as his future (the good AND the bad)? You want to make sure he can communicate his doubt or fear with you, and not hide the "bad" feelings...I'm sure you have little pangs of doubt, too, and it's all in the name of a healthy, secure, long-term relationship.