I hope this message finds you well, present circumstances excluded. I am a licensed attorney with over a dozen years of experience handling matters of this nature. It is a pleasure to assist you today, though I wish the circumstances were different.
If you feel threatened by him, which seems like a very reasonable feeling based on what you have shared with me, you should seek a temporary restraining order against him. The temporary restraining order, or TRO, is designed for situations like this one to protect you from both physical harm and mental harassment.
Once you apply to the court and receive the TRO, a hearing will be set for likely two weeks out. At the hearing, you can argue your case and have the TRO converted to a permanent injunction - which will keep these people away indefinitely.
Remember too - you are the wife of your husband and unless a court says otherwise, you are his guardian in this circumstance. His family has not right to any medicaid payment or other financial instrument that is assigned to you guys. It sounds like they are attempting to gain from your husband ill fate.
I suggest you seek an TRO as soon as possible from a court in your city nearest you. Speak with the court clerk about filling out paperwork for an TRO against these people.
Let me know if you have any other questions or comments. Please also rate my answer positively (THREE OR MORE STARS) on the ratings bar on your end so I can receive credit for my response from the site.
Best wishes going forward!