Yes, you can come to Qatar if you have a valid Qatar ID. You can stay here as long as your husband does not cancel your RP or your ID expires. Since I believe your husband is your sponsor, he can cancel your RP anytime and send you home. You cannot fight your case in Qatar as you are not a Qatari national and you have no legal options here in your matter. You may take you husband to the court in your own country and for that you may need help from a lawyer there. Going to court in your own country is a long and painful process with only the lawyers getting most of the gains.
After reading your story, I guess you may have lost almost everything in cash and valuables. You may be able to salvage your marriage with the help of some family members.