DS1 is now approaching 6.
He was a velcro baby, and was pretty much sling carried for his first 6 months (then he was crawling).
He was a nightmare sleeper, and I was often found on his floor, or him in our bed.
From about 3.5, he started sleeping through, and stayed in his own bed, but if DH was travelling with work, the first question he would ask would be if he could sleep in my bed.
He is still very much a Mummy's boy. But he is also very, very sociable, and will chat to anyone, anywhere, and bounced off into school without looking back (despite often moaning at nursery drop offs)
So, I would say the attachment you have with DS isn't an issue, but you and DH need to come up with a parenting model which works for all of you.
If DS moved from a cot bed to a standard single, would you be able to share with him occasionally? Personally, I think loosing the single in DS's room was a mistake (but then we still have a spare double in DS2's room, so i would say that!)
How much over 2 is DS? Would he understand that he can only come into your bed after (say) 6 am for cuddles, then up for the day, and noit for sleeping?
It also sounds like you and DH need to spend some time together? Can you go out for an evening, and leave DS with a babysitter - we've used one of the apprentices from nursery very successfully - on a semi regular basis to guarentee time with each other (even if all you talk about is your son!)
Sorry, bit of an essay. Hope some is helpful.