Replying to Coming off an injury this season.

Not many parks are open yet near me but I have been riding some rails in my yard for a little while but I can only hit my flat rail. I hurt my hip last year and I was out for the end of the season, my doctor said that I would be fine to ski so I am all clear I guess. I am fine on the flat rail but I'm afraid I'm gonna slip out on the down flat down because I feel like I'm gonna slip out and fuck my hip up again. What should I do?