Panicking about my sons first residential trip

[Milkandcornflakes]

Good evening all..I have a 8year old son with autism ..hes on the lower functioning end of the spectrum and I'm a single mum...I have been refusing this trip for the past few years but I have decided to do it for him (to have the life experience). I'm having major wobbles tonight as we have never spent a night apart ( except when I was going through cancer). He shouts out for me constantly at home and isn't a great sleeper and has severe food issues ( phobias and limited diet)..I'm sitting here thinking about him crying for me at night and it's so upsetting. The staff he is going with are his usual key workers from the respite centre..they are going to Woodlands Adventure in Walsall,which is an outdoor activity holiday which I'm sure he will enjoy in the day..I'm worried about his self care and his little quirks and rituals..Hes going on Monday and it's my birthday on Tuesday.
Unfortunately I will have to use these couple of days to dash from London to Yorkshire to see my dad who is in hospital with cancer and heart failure.. has anyone let there kids go? I'm torn...
Hes had a difficult week behaviour wise too so I'm exhausted.