Translation of revanchistisch

I hope you could understand my last letter to you. You see, when I write in Spanish I am not very confident. I always question myself and each and every sentence takes about fifteen minutes.
Please postpone by three days to one week. I am abroad, and Loraine can't come with the baby. We are available from august 31 until September 23 (except September 16) where we have other commitments.
Your offer seems interesting to me. The language exchange is one of my future projects, so that we will contact you later when I am ready to discuss the ways and possibilities of learning together.