This is the best advice I think you've received. Yes, the site needs work, yes, you need to redo the copy, but to solve the chicken and egg problem you need to contact people trying to hire freelancers and post jobs for them. Consider it a feature of the app. A walled garden that solves your chicken and egg problem as well as making your service a multiple better than your competitors.
When you can't keep up with your listings then you have "new problems" and new problems pay way better than old problems.
When you can't keep up with your listings then you have "new problems" and new problems pay way better than old problems.