Hi..
Thanks for the query..
Severe itching all over the body can be due to
allergic reaction that can be probably due to allergy to any food or medication, skin cosmetics, detergents, soaps etc..
Also if you have
head lice it can cause itchy scalp and medicated lice shampoo can help you.
For itching you should consult an Emergency room and get a
blood test done for allergy that will help in ruling out the cause of the itching and treated accordingly..
For now you can take Benadryl to reduce the itching and apply Calamine lotion to soothe the skin..
For a boil on the bikini line that can be an ingrown hair or hair
follicle infection, you can apply antiseptic ointment over it so that it gets healed and keep the area clean and dry..
As far as bot fly is concerned he larvae can be found under the skin and caused painful raised lesion on the skin, but your symptoms are not looking consistent with it..
So it is advisable to consult an Emergency room for a clinical examination once and treatment will be advised accordingly..
Hope this helps..
Regards..