My doctor gave me a prescription
It has two T's and two Dots over the t"s
With grams twice a week what does that mean

I'd recommend either calling your doctor or talk to the pharmacy that dispensed the medication. Either of them know what was written on the prescription. You do not want to leave many medications to chance, you want to get it right the first time. The wrong doseage of some can either do nothing, or kill you.

That means that you are to take two grams twice per week. The 2 t's with the dots above then is a medical abbreviation for the number 2.