The increase in the liver enzymes may be part of severe vivax malaria itself since you had a fairly severe bout with significant fall in platelets. You would also need a course of primaquin later on after checking your G6PD levels for radical cure to prevent a relapse.
Liver enzymes can take 1-3 months to settle. You do not have to be on a very strict diet. We normally advise to refrain from deep fried, non veg or chinese food containg MSD. Otherwise home cooked food is absolutely alright to consume-take vegetables and fruits as you desire. You do not necessarily need to be on boiled food. Monitor your LFT.