Wow, you have a lot to deal with! My kids were 10 years apart.
First of all, realize that your kids pick up your moods very easily. I was a single mother for years, but I had a lot of support from my family, emotionally and financially. Do you have a support network? If not, is there a mothering group you can join in "real life?" The first thing to do is to make sure Mom (that's you!) has the support Mom needs. If Mama ain't happy, ain't nobody happy. You can't deal with all this unless you have support. Does his dad pay child support? Send videos over the computer? Anything like that?
Do you have access to counseling? I have been to therapy off and on, as needed, for certain troubling events in my own life. It can really help to have someone neutral listen to your problems. Even a kindly minister. As long as whoever it is doesn't judge you, but just listens to you and validates your feelings (if not, fire them! I have fired a therapist before, at least twice, and then found one who I liked, so remember, you're the customer and it's their job to provide you with excellent customer service.).
My son used to get very angry when he was little. My babysitter finally pointed out that he seemed embarrassed. For example, when Sean fell down and scraped his knee, my first instinct was to pick him up and hug him. He would push me away and scream even louder! My sitter told me to leave him alone for a few minutes, as long as he wasn't seriously injured, of course. That was really hard for me to do! My daughter loved it when I hugged her after she scraped her knee.
Well, one day when I was picking him up, I was in her front hallway by the door, and Sean fell down outside, where he was running around with the neighborhood kids. Sandy, my babysitter, said, "now wait, leave him alone." I did, and then she said, "look."
Sean was sitting on the top step, surrounded by about 5 or 6 little girls, all asking him if he was okay, LOL!!! He was lapping it up, too. Sometimes boys need their moms but also need their moms to let them learn how to work out their own problems. After I left him alone for a couple of minutes, keeping an eye on him out of the corner of my eye, he would come up to me and say "uppy, uppy!" That was when he was about 2 or 2 1/2.
Just watch him around your microwave oven. I took something out of my microwave once, and Sean grabbed the glass plate that the food rests on, and winged it onto the floor. Glass everywhere! I don't know why he did that, I think he just wanted to see what would happen, but it scared the heck outta me! LOL. I picked him up to keep his feet from getting cut, and put him on the couch while I cleaned it up. He loved Rugrats, and Raffi and the California Grapes on tape to go to sleep to. He would say, "more music! more music!" and I would flip over his tape and he was usually asleep by the time the 2nd side was done playing. Usually. LOL.
You sound like a great mom, just a bit overwhelmed. Try not to worry so much, and do look for help and emotional support from family, friends and neighbors. Just make sure they are true blue friends and not busybodies who try to put you down, okay? You can do it, Mom! ((((hugs))))