Brother not allowing to use share of property duly registered. Advice.

Sir we are having a farming land in which we are three brothers having shares in the same land. And the partition was already done in front of some relative as a witness and all partion was written on stamp paper with signature of two brothers and witnesses. In that partition we mutually decided to use the farming land for four years by one brother after completion of first four years the second brother will use that land. All is going well but after death of my father and mother my both brother are united along with my sister and they are not allowing me to use the farming land. They are putting new and unnecessary bills in front of me which are of not my concern. And they fighting with me and told me they will kill me and my family if we put our steps in the farming area. Now please guide me with the proper way to get my property with me. So that I am also able to use that land. Or else show me some other path that no one can use that land.