I've gone to a gi doctor and can't afford the medication he prescribed but i'm getting constant pain on the left side and under my belly button....

If you have already: Seen that doctor, and they have prescribed an expensive medicine, call their office again and explain the situation and ask him to prescribe or suggest a cheaper alternative. It is worth the try, and he may know an alternative, or be able to give you samples, or a coupon, or voucher. The maker (pharmaceutical company) may have a program to give medicine for free to those who can't afford the meds.