It is possible that a court will rule that you were/are a tenant at will(month to month) due to 1)the length of time you lived there and 2)that you paid rent "in kind" by doing maintenance. Sharing in food cost is generally not considered. You would then be required to be evicted: http://www.rentlaw.com/eviction/texaseviction.htm
But a court also might rule you were a houseguest, living there at the pleasure of th owner. Kind of doubtful in your case, but strange things happen in courts. In that case you would be trespassing and subject to pretty much the treatment you got plus even arrest.
Beyond all that though I can't help but assume that your accident and current disability have something to do with this. There is way more here than a landlord tenant case. And without prying into your personal life, being that you're family, have you both considered counseling of some sort?

