I would get a new vet, your snake looks fine and if he ate in march, no biggie. Dovah went off feed for 2 months and he's only a year old. I didn't worry at all, and just kept offering until he finally took again.
Force feeding is an absolute last resort. If your snake hasn't eaten for almost a year and has dropped so much weight he's lost muscle tone, or for babies that refuse to eat and need help getting started.
Don't worry too much about this, jut keep offering food every feeding day and eventually he'll take again, and always try feeding live rats then try mice before trying to force feed anything! Your snake looks to be a fine weight to me. Snakes can go several months before food strikes become a problem.