Please help, moms making me get the depo shot.?

So, I was on birthcontrol, but was getting busy and caught up and missed a couple days and mom was all freaking out and put me on the depo shot, I have gotten one already. And I have heard and read that this shot ruins your insides ,so when you wanna have kids when you get off it, you can't. Guess it makes you unfertile, and my mom ALWAYS talks about me having grandkids when im older, and I don't like baby's or kids right now, but I know when im older its going to change. So, I want to have kids when in years to come. But, I don't want to risk the chance of becoming infertile, and I don't think my mom will understand if I ask her to get off it, she will think im trying to get pregnant, are there any other options? Or things I could say to her to not have her thing wrongly?