is this cruel for my 18 month old?

Fiona

my son sleeps in his own single bed. we had to start by lying with him till he fell asleep,then sitting next to bed,then lying on floor and gradually moving out the room until he would eventually we could give him a bottle, a kiss and leave.

the pat 3 nights he's been terrible. screaming when we go into his room, dragging us into his bed, and not wanting to let go. he's well and not teething, but we have been keeping him up slightly later than normal.so tonight I bathed him, got him changed in his room. we sang some songs and then I put him in bed with milk and left. he cried for a second and then I watched him go into bed, then out, he played with his toy car for 20 mins and then lay on the floor and went to sleep.... I feel terrible. should I just have stayed in with him?