Prolonged period after plan b

So after plan b I have a prolonged period last September I got my period lasted for about 10 days and the bleeding stops on Sept 17. And now this month my period starts again on October 1 with pink spotting and then confirmed that it was my period on October 2 and it's not heavy and not light but in a normal period until now I'm bleeding😭😭 I'm so tired it's my 8th day of my period, right now I'm feeling dizzy and shortness of breathing and also I'm so weak right now