I would remove one side off the for, butt it up to your bed (or spare bed in baby's room) and accept that until you can get him settling in his cot, you will be in bed when he's in the cot.
Lay baby down to sleep, lie next to him on the bed, give dummy for comfort sucking and cuddle right into him until asleep, the extract yourself.
This ^ would be my start point hit gradual withdrawal.
I started like this from newborn. It took until 12 months of gradual changes until baby could be put into the cot standing, with dummy, I'd leave and baby would go to sleep.
No crying at bedtime, ever. No grumbling, whinging, whining or whatever else people might call crying. Gradual Withdrawal really shouldn't be causing any distress. If it is then you have too much withdrawal, not gradual enough. It's a long, long, very slow process.