Metformin & weight loss isn't working for me!

Yaz • 28y | Baby boy born 12 June ‘19! 🧔🏻👩🏻🐱👼🏻👶🏻
I work out at least 3 times a week, eat healthy & have been on 500mg Metformin a day for 6 months, down from 1000mg per day before that for a year. 
Periods haven't shown for 3 months now! Like wtf 😡 What else am I supposed to do? I'm not losing any weight either, stuck at a firm 154lb for the past year (I'm 5'3). TTC looks like a joke with these issues. 
Does anyone have any insights on what to do? I'm so so close to giving up hope.