I personally have had in law problems. My wife now was told that she could have done a lot better, and there is a very long story and many incidents big and small that has happened along the way. You are so right, it does cause a huge strain and it has almost caused us to go our separate ways at one time. All I can say is trouble caused by in laws in my experience is from jealousy. They did not want her to live her own life. I could say a lot more in a email or other ways, but never ever let inlaws destroy a relationship. It is not right. At the same time the experience could make you even stronger. As far as returning the ring. That is harsh and very strong message. Whenever two people get hurt it is almost like a vicious cycle but for me the best way to get rid of all that stress is to keep away from the people who are causing trouble and maybe they will come around. Good luck in the future.
Joe