You sound very level headed and I think you are right that you need to work out the issues you have before you move forward into marriage or a baby. If you do go ahead and have a baby, if the relationship were to come to an end, the child would still be there to deal with for the rest of your lives.The problem is , I suppose, trying to get your partner to see this! Try explaining that you want stability and 'settling down ' too but think that these things are worth waiting for to make sure they last forever, rushing ahead could make things better in the short term but lead to longer term upheaval.
Would he agree to speak to a relationship counsellor? I know these things are not for everybody, but it might help to talk to somebody who is not emotionally involved.