Suggestions needed

Hi I am new to this forum. Read some of the discussions and found them very helpful.

I have a 11 years old autistic son who now will be transitioning to the secondary school.He goes to special primary school. Although my son has improved a lot in the past years but still he has many issues like sensory overload, picky eating , unwillingness to follow directions, no sense of danger, most of the day to day tasks like brushing teeth ,taking baths etc he can't do  .Can be aggressive at times (scatching, spitting,pulling hair ).He is not completely non verbal but can put few words together to make simple sentences. Most of them are repeated phrases. He is good with numbers. He can read and write but not willingly . It is so hard to keep him occupied at home as he doesn't want to do anything and will spent most of his time watching Ipad or play with his blocks.

As now we have to select a secondary school ,I am not sure what to look for.Some of the schools that we have  visited don't seem suitable for him. I think he might be suitable for residence school but the thought of him being away just kills me ......I feel like a failure. 

Please parents whose kids go to residence school....have you seen tremendous improvement in your child behaviour? Are they now able to do their day to day tasks independently?

Need some encouragement