Irregular Period

Soooo ladies I need your help, I have already been to my doctor and your resolution only worked for about a week. I have always had irregular periods because I have been on birth control. But never have I ever had my period for a whole month and now that’s happening. I am on the Nexplanon birth control and when I first got on it my periods were normal, they would only last a week. But now it’s just TOO MUCH! And I want it to stop so I can “get some” you know. Today is Oct 16th and I have been on my period since Sept 23rd literally almost a whole month. I am trying to make it stop or figure out ways to shorten it or something. My doctor put me back on my iron pills for anemia and she also told me to take birth control pills for the nexts 3 months because it will balance my hormones and stop my period. It stopped it for about a week and then it came right back for another month ! I am just so sick and tired of it and it will be heavy. Please helppppppp!