It's obvious you are not happy, and a baby is certainly not going to solve these issues, only add to them.
Why not try Relate, and see if you can get your communication back on track with some professional help. It has to be worth a try - you are in a 'nothing to loose' situation right now.
Have a go, and if it doesn;t work out, then you know this is not right for you, and if you have both beeb conselled, your partner will see it as well.
in an adult relationship, staying there because you don;t want to feel guilty is really not an acceptable reason - you may have to bte the bullet on this one.
You may find your partner is well aware things are wrong, so he may welcome a chance to try and get your relationship back together again.
Good luck.