11 years old and struggling

I have an 11 year old son that I just want to give away more often than not. When I say "give away" I wouldn't actually do it nor do I want to be done with my son but i need help and any kind of advice.

Backstory-- my sons dad and I were together from 13 to 23. I got pregnant at 16 and left his dad for cheating and he was on dope really bad. His dad spent 2 years in prison, got out and seen him maybe 5 times and went back for a year. He's back out now and I've let them see and talk to each other but my son is not allowed to leave with him. We can all sit in the same room without being petty or nasty with one another.

My son struggles in school with work. I have him on concerta but it just doesn't do the trick. This kid will lie to you about ANYTHING and stick to it even after he is caught. You can catch him red handed and he will still lie. He pilfers thru everything. He will throw someone under the bus to save himself. He will bully other kids that he knows that he has an advantage over. Not fighting, just mean things, but it's all the same to me. I have not raised him this way and I'm at a loss on what to do with my child. I've taken things away, I've grounded him, I've whipped him. I'm at a loss!I just got a call from the school today to have a parent teacher meeting due to him telling them that he cant focus and he's having "home problems" I have no idea what this kid has went to school saying.

When he was in preschool, he told the principal of the school that a snake bit him and I didn't take him to the doctor. And no, that did not happen. He took a clear round paper clip container to school and told them that he had moonshine in it when he was in 3rd grade. So there is no telling what he has told them