Re: starting daycare at 17 months
I suggest choosing a provider who makes you feel comfortable leaving him. Then, try to leave him there every now and then starting now (for mornings only). Nine months is a hard age, they are definitely Mama's babies by then. Some kids though, are so social that they love to go to daycare to play.
Mornings are always much easier than afternoons. Kids do awesome, then sometimes have a hard time at the afternoon nap. Then, that's all they remember later. Nap. Not that they had fun the rest of the day, just nap.
So, if you can, try dropping him off at the daycare for a few hours in the morning. Once a week would be great if you can. Try to enjoy your time to yourself, then pick him up before lunch or right after lunch.