I am overweight and take prozac (fluoxetine) and adderall. i've been having a strange throbbing pain in my left thigh like a burning stinging ?

Nerve: This may be a pinched nerve(meralgia parasthetica) which can be seen in overweight people or people who sit for prolonged periods like truck drivers. If you have further concern, see a neurologist for evaluation and advice.

Shingles?: There isn't enough information to answer your question, but if this has been a problem for just a day or two, and you have had no injury to the area or to your lower back, I would consider possible shingles. If you notice any form of rash in the area, call your doctor or a dermatologist right away.