My Gums still receding?

Recently I went to the dentist and they cleaned my teeth. The doctor said I need to brush my gums and around me gumline. Since I went to the dentist the gums around my lower front teeth have receded and I'm worried. I really cut back on sweets and I try to brush my teeth at least twice a day. My gumline around my lower teeth is really low and I don't know to do about. I think I'm brushing to hard. Can anybody help me