I really need to know

I have been chatting, emailing with people online for several years now. I even met a few of those guys and one time I fell in love badly. It took me forever to get over him but I was willing to try again. The thing is, I have two children and therefor I don't have much of a chance to go out and meet someone. So I thought online dating would work just fine.

I think I am decent looking and do get responses from guys. AT FIRST!

And here is the problem, which I just don't understand at all. I start emailing with guys and I never lied about anything on my profile. There is my real picture, my real age and I even mention having two kids. So I start emailing and sometimes I catch a little fire...and get involved and really want to meet a certain guy. And then...he just stops writing. From one day to the other and I have no idea why. Of course I usually read my last emails desperately looking for something might have said wrong or done wrong. There is nothing. I didn't talk about getting married or having kids or anything else that could have scare a guy away.

So I am asking you guys why? Why does this happen to me? What went wrong? The funny thing is I know pretty fast, I just got hurt so badly in the past that I can just sense these things now.

For example...I was emailing with this one guy and he wrote me every single day for the first week. And his emails were very very long. Not just blabla...but really deep going, if you know what I mean. So one day I realised he had been online that day but didn't even bother to read my email. It still showed as "unread". I knew right then and there that that was NOT a good sign, and I was right. He wrote a few more times after that but it took longer and longer each time for him to respond and I just knew this had no future...but I didn't know why.

He seemed interested at the beginning but then it just stopped. This really bugs the hell out of me because it has happened to me so many times, you have no idea. Any advice?