Others might disagree with my approach - you have to do what works for you - but I always tell my husband everything. Granted, we've been married for almost two years, and together for another 6 or so before that. I don't know how long you've been with him, and I'm not really sure how much I told my husband in the beginning.

I think I would at least tell him your thoughts on it. How you want to isolate because you don't want to be a burden to him, and how you're worried about not being a good girlfriend. Don't let the negative thoughts about how you think he must feel cloud your head. If he didn't want to be with you, he wouldn't. I realize how incredibly tough it is, but you have to focus on re-wiring your thought patterns away from negativity and focus on positive (or at least neutral) things. If you start having negative thoughts about your relationship, try writing them down and then write down a counter statement, such as "He doesn't love me." "That's not true, he loves me very much." The act of writing it down always helped me.

I hope that helped a little. I understand how hard it is for both of you right now.