Avoid taking rich diet and oily diet. Daily physical exercise

Yes it is because of covid. Post covid there can be symptoms or raised parameters seen with in 2 to 4 weeks after the 14 days qurantine / Isolation period. This can be due to the limited activity during the Isolation and good nutritional food given by the relatives. There has been evidence of Triglycerides going high and even sugars going high in people who have diabetes and other chronic diseases. There can be neurological symptoms like headaches and forgetfulness and giddiness also. All these are part of Post Covid Fatigue Syndrome so it's advisable not to neglect them.

Not because of covid Avoid oily and fried items Avoid spicy food, Regular walk and exercise Contact online immediately Recheck after three months If raised can start liponorm 10mg

Unlikely due to covid. You probably have familial high cholesterol. May need treatment