Irregular periods. And lose my weight.

Hi, I have been suffering from last couple of years with irregular periods. First, I used get alternate month periods and layer it turned to occurring once in two months. Also,  my bleeding quantity is very less. I bleed to an extent only on 2nd day of my periods. When i consulted a gyenic doc in february, She prescribed folic acid tablets to be taken one every night. I got my periods as long as took tablets. But now i stopped taking them and periods also stopped along with it. Last time when i got my periods is on march 23rd 2020. Due to this, i started gaining body weight.i rose from 54kg(my normal weight during regular periods) to 70kgs(increase in last 4years due to irregular periods.) I do not have diabetes or thyroid. My blood pressure is normal, sugar levels are normal. But i have low haemoglobin%.i am unmarried. I do not eat outside. Only home food. Iam currently 33years old. Please help me get regularperiods and lose my weight. Thanks, Satya