Opening up to someone you work with about personal issues - is this huge mistake?

My superior at work today e-mailed me asking if i was ok - I guess he noticed I was visibly upset in the office, even though I was trying to hide it. I've been going through depression lately and haven't been able to control my moods so easily - when I get sad, I have a hard time hiding it. I told him I was having a tough day but i was fine, then he probed more and asked what was wrong and he would be glad to try to help. Because I was feeling so down, I maybe wasn't thinking so clearly and did tell him that I was just having a low time in my life right now and struggling with feeling lost and things in my life not really working out. I now deeply regret doing this - as I don't think its a good idea to open up this much to someone who's above me. I feel so foolish. He did not respond after i told him that, and now I'm kind of sick with regret. I'm not someone who opens up easily and I feel like this is a bad idea that he knows this about me - that maybe it may negatively affect how he views my work abilities. Ugh. He seemed like he genuinely wanted to help - but with no response from him it seems I may have freaked him out. Am i overreacting or did I really mess up by doing this? I don't want to be the 'emotional female' at work - I want to be respected and now I feel i screwed that up... :(