I suppose it could be ADHD, but several of the things you mentioned don't sound typical of ADHD. It would be a bit early to really notice at this age, anyway, since toddlerhood exhibits most of the symptoms of ADHD. I would recommend seeing a mental health professional/your pediatrician as it does sound both you and your son could benefit from help.
How old are your other two kids? If he is the oldest, a lot of this is probably about lack of attention because the others need your attention. If he is the middle child, probably still the same reason. Its very difficult to discipline when the key word is consistency and you are torn between 3 kids. They talk about the terrible two's - well, the three's can be worse cause they now can figure out how to play the system.
You need to divide and conquer. You can't deal with all three at once. As you said, "i just give up as it is hard work." Yes, it is. Trouble is, is that the giving up has let him get his way. Its really hard for you because you can't be patient, cause you have other kids with needs. The nursery is really important. Carry him kicking and screaming if you have to. They are used to it. I bet he stops soon after you leave.
He could be a hyper child or he could be kind of normal for a 3 year old. Do you have an older one for comparisons?
There are a lot of things that you can do to change his behavior. They all take time and consistency, but its worth it. You might try reading, "SOS Help for Parents," by Lynn Clark, I think you will find it helpful. Good Luck!
Thats typical 3yr behavior, wait a year till he's 4 and see if he levels out. If he's still a handfull that would mean that its just his personality. Meds for add adhd are to be used for academic or life skill aplications. Its just a phase. Keep Strong!
The youngest you can be diagnosed with ADHD is typically 5-7 years old.
Wait a few years.
Medication on such a young child also - I wouldn't do it.
You could end up with more problems down the line.
Some children are not ready for school at age three, so you might consider taking him out for a year. In any case, nursery school is not essential.
I am sorry you have such a difficult child, but labeling him ADHD and drugging him is not the answer. He is in a very early developmental stage. If he is eating a lot of sugary things, stop that immediately. Sugar can lead to many behavioral problems. Otherwise, just stick it out for a couple of years. For your own benefit, try to get away from home for a few hours when you can. This will take the pressure off you and improve your ability to cope. Mothers need care too.
While nursery school is certainly not essential for his educational development - it does help with social skill. More importantly (besides giving you a break), it also provides feedback on how he reacts to their discipline measures (compared to yours). If they can't deal with him, once he is there, and they are experienced - then it may be time to consult a professional.