You have to learn to relax, if the pain is always in your mind you will never enjoy it. This is something that will take time to learn, like a couple of months. You have a good start with the toys just keep at it. As far as the feeling of having to go/bloating, part of it is the rectums natural reaction and you will learn/train the rectum to not feel this way. Kind of a mind over matter deal here.
As EnterTheFist stated, stay away from numbing products. They are just not worth the risk. Better to start of slow with small toys and work your way up. When you can use a toy that is a little bigger than your hubby without any pain then you will be ready, not until then.
Pick up this book
, it is jammed packed of great info on anal play and will go along way in teaching you everything you need to know.