A.C.
Has he has an ear infection yet? You might want to get into the pediatrician's office to have them take a peak. My daughter often had persistent fluid in her ears and would take some time to develop into an infection. It was never a problem...until it was time to lay down.
Separation anxiety is normal, and they certainly don't come with a manual! I try to rule out physical discomfort and then just roll with the punches.
Some children do require more physical contact. I found it easier (in general) to just give my daughter extra snuggle time rather than try to "train" her. I also used a buckle type mei-tai carrier or a moby wrap at this age. It left my hands free to do what I needed. My daughter quickly learned that if she wanted to be up then it was going to be in the carrier. A 10 month old can quickly get bored by this scenario and will choose to play rather than ride around on mama's back.