What you did that was wrong was allow him to take over the household. He won't "allow" your husband in the bed? Sorry, K., this is all your fault.
Time for some tough love. Put his crib mattress on the floor and tell him that he has to sleep on it. No, he cannot come in the bed. Yes, Daddy is sleeping in the bed. If he has a fit, ignore him. Warn your husband and make sure that he ignores him too. No yelling at him, no cajoling him, no talking to him. Just ignoring him and NOT allowing him in your bed, only on his mattress on the floor.
It's going to take a good while to institute this change. You have let him rule the roost, and now you have to pay the price. Don't give in. DON'T let him in the bed and don't let your husband leave. Go to bed earlier if he cries for a long time so that you and your husband end up getting enough sleep.
Once you have him actually sleeping on the mattress, eventually move the mattress closer to the door. In a few months, move it into his bedroom. Keep your door open. He'll keep coming back in, but you need to walk him back in his room over and over and over for a while until he finally stops coming in your room. DON'T lay down with him. Ever.
If you can separate from him at nighttime, it will be easier to separate from him in the daytime. Start with nighttime.
Don't ever let your kids come between you and your husband. If you put your kids before your husband, they will not respect your husband. He will just be in the role of moneymaker in the family if you do this. It's a very bad example for your teenagers, quite frankly.
As he gets a little older, he may become more independent. If this continues during the day, you need to stop jumping at every demand of his and tell him "Please wait a minute, honey." He has to learn that he is not the center of the universe. It's your job to lovingly but firmly teach him that.
Dawn