This is a long one so please, please bear with me....OOH where to begin.

My son at 17 months began to start waking during the night and started showing signs that he didn't really like sleeping in his cot, so we had a spare queen size bed in the spare room and thought it would be a good idea to start him off in there (I was a little concerned about him falling out so thought it would be better than a single bed for the short term). He did extremely well and once again began sleeping through the night with out any hassles at all for 6 - 7 months.....BUT then we purchased a single bed for him just after his 2nd birthday and the problems began again. At first he loved it, (the bed was a little higher so he needed to learn how to get off it safely) he fell off the bed twice while jumping on it and being silly and this seemed to greatly effect his confidence. Then it all began...he started to wake during the night and refused to go to sleep unless my DH or I laid in the bed with him. We would take in turns laying with him until he would drift off to sleep and then quickly vacate the bedroom, but his sleep never lasted for long. With both my DH and I working and desperately needing our sleep the only alternative was to put him in bed with us, so we could all get a good night sleep. BUT we have made a HUGE error with not persisting and so now just cannot get him out of the habit of co-sleeping. This inturn effects my relationship with my DH and with another baby arriving in less than 4 months we need to do something....BUT WHAT???? I am at a loss at where to begin.

Please Help.....advice, ideas, have you been in this situation, Would love to hear from you.