Sounds like he is dealing with some anxiety..My oldest has this and has had alot of trouble when it comes time to go to sleep. What has worked lately for him is reading before bed. It helps to get the mind to unwind and to stop focusing on all the daily stressers..

i recently have started having problems with my 8 yr old going to sleep its not every night at least 2 nights out of the week? not sure what going on and she will only sleep with her older sister and insists on sleeping with me some nights

My son had this for a while. I tried to make his bedtime routine as regular as possible and include a hot bath or shower often. He also needed to eat a lot during the day but less near bedtime. And I sat with him in his room and we chatted, no questions or anything, eventually he would say what was on his mind. Once he laid down his little burden, and once he said it, it was not nearly as bad as he thought or I imagined, he could relax. I just needed to show that at the end of the day I had some time and love for him that maybe I had been too busy to show before.
The other issue was food allergies, and once I changed his diet he slept better.

I went through this when my daughter was in 5th grade. They had so much more homework, new school style, middle school and everything. I was at my wits end because when she finally did go to sleep, she was waking up every couple of hours and only secure and sleeping well when she slept with me unless my husband was home and then found her climbing in with her little sister in the night. I knew this was not good for anyone. The Pediatrician recommended Melatonin. I have to say, it was awesome! After she had it a few times, more me pushing and coaxing, she realized the benefit. She's 11, nearly 12 now and she still uses it sometimes, but not all the time. She always reads before bed, but it's not always enough, so she'll tell me if she needs it.

It's natural and just an enhancement to what the body uses to fall asleep. It's not a sleeping pill, so she will occasionally still get up after she's used it, but not nearly as often. Check with your Ped, because it might help a bit. Otherwise, staying calm really helps as I know how frustrating it is when they won't go to sleep and they need to as well as yourself.

Good Luck!