This is a common concern. The answer is equally simple. If after 2 months, you have had no orders, you have nothing to lose by changing your gig. (Ranking well doesn't matter if you're getting no orders!!). Concentrate on a well written gig desc in perfect English, choose your keywords and tags carefully and do as much research as you can - i.e. look at what your 'successful' competitors are doing then emulate (don't copy) it .... Good luck.