Reverse Cowgirl Help!

Sammy • Wed, Sep 02 • Soon to be 21, been a mother to my little man since age 16. I am engaged to the love of my life/highschool sweetheart & we have our miracle girl on the way! Due St. Patrick's Day!

I have tried this position a few times and it never works out right. Is there any tips or advise on what to do? Thank you!