Sounds like a good idea to live apart and work on your relationship.

Keep talking,don't let bad feelings build up,work together as a couple and as parents,be active particpants (sp) in your lives,don't just sit back and watch the time slip away.
Make a plan on what you can save,a little amount every week will build up.

Set your sights on your future,I stress that you need to keep talking,and perhaps when your talking again to talk about how you both argue,and when things are getting heated that one of you realise this and say something..

Good luck to you both.