I put him to bed some nights and cry

Loving my son is easy, living with him is not.
Some would say he is controlling, a bully, self centred and aggressive. These would all be correct.
He is also frustrated, anxious, stressed and agitated.
No anger course, or therapy or counselling will help him.
He is 8 and can not speak. He is still in nappies. He has no sense of danger. He can scream for hours, smear, attack and demolish all in one day.
Yet he can laugh a deep laugh that is so contagious he makes everyone smile. He can flap and find utter delight in lift doors opening for hours.
He is the apple of my eye and the delight of my heart but some nights I put him to bed and cry. 
I cry for the life he is missing out on: The lack of friends, the inability to read and write, the fact I have no idea when or if he will ever be toilet trained. I cry because he is misunderstood and judged so much. I cry because he can not tell me anything like how he is feeling or what he likes. I cry because he is so vulnerable and that scares me. I cry through exhaustion having to constantly guess what he wants and why he is so upset. I cry through years of sleep deprivation, lack of support and the stress that something as simple as an open door makes him throw himself down the stairs in distress.
I put him to bed and cry because I do not want him to see my tears. I never want him to feel he disappoints me. I never want him to feel rejected or unloved. 
But I need to let the tears out. Pretending this is ok is not helping anyone.
My son has severe autism and it is very hard. My son has neurofibromatosis type 1 and that scares me. My son is vision impaired and that worries me.
His list of diagnosis and difficulties is comprehensive. He requires 24 hour care and relies on me for everything. He will need care all his life and his condition is progressive and unpredictable.
He brings me great joy but caring for him exhausts me.
Loving him is easy, living with him is not.
I love him more than words can say but I put him to bed tonight and cried.