I inherited a farm as well as a listed manor attached to it. I'm in the process of selling the manor and much of the fields after 10+ years of looking for a buyer. Here's my .02:

1. You should not feel obliged to continue your father's work. You're a different person and I'm sure your father would prefer you to be happy above the farm staying in the family. If you think selling the land is a better option, do it. If you built your own career, don't sacrifice it for the farm.

2. Consider leasing it. I'm in the EU so I get subsidies (even if there's nothing there but grass), plus a lease from people who want to actually grow something there.