I'm not a single mom, however I've gone to WDW without my DH several time. The first time I brought my then 4yo and my sister met me for most of the trip. The following year we returned and met my sister and my mom, so also had extra adults. In May I brought him back down and it was just the two of us for the whole trip and that was great. Another time I brought my then 11yo (and once my college DD, but that's a little different).
It was tricky when I brought my 4yo and my sister wasn't there. IE, one time we had our food and were eating at a foodcourt and Jake had to go to the bathroom.

I found a CM and asked him not to clear the food and we went to the restroom. Things like that were a pain, but a person learns to work around them as much as possible (go to the bathroom before ordering

).
At least your kids are a little older. It was much easier going with Jake as a 6yo than as a 4yo. For one thing, he could ride all the rides as a 6yo (and he's a daredevil and did). Your kids are old enough to ride without you if you don't all want to go on it. You can all walk through the queue and can then meet at the exit (works really well at RnR, etc).
Going by myself, with Jake, was out of my comfort zone for sure. I was very nervous about it, but it's very worth it!