In reply to Camlan, "Once I realized that other people expected me to say "Yes" all the time, but had no problem saying "No" to me, I learned how to say "No" in a hurry", this was also my wake-up call. This had to happen more than once for me, but once I made the connection, the doormat was gone. Interestingly enough, I never heard from those people again. And good "dingdangity" riddance.
Best of luck to you, OP.