VERY new to this need advice!!

I recently bought my first cup on a group co op. I think they said it is similar to the mooncup brand but are unbranded. I took advice from someone and inverted the cup after trimming the stem off completely and still feeling uncomfortable. then, I was ok for a bit it seemed alright but I had only really tried it out at home and I decided to go out shopping with it in. as soon as I was out and about walking and lifting my kids, etc, I felt it coming out. it was being pushed right out. I always had trouble with tampons, even as a virgin, and I didn't like to use them. I think I might have a lower than normal cervix? I am wondering if you ladies have any tips. I am determined to make the switch to a cup and say goodbye to pads forever!!! for many reasons including waste, comfort, and ease. everyone I know loves the cup, and I really want to make it work for me. feeling discouraged....any ideas?