Tampons

****TMI****

I got my first period in February of this year, and I’ve had my periods every month except for 2. I want to start using tampons, but I’m so scared. Backstory: I used to use Pocket Pearl tampons (so they were small) and I got one in, but it was super uncomfortable and hurt. I got it out and since then I haven’t left in a tampon after inserted. Now: I have a close relationship with my mom so I did ask her for tampons (they are Tampax active so they are super tiny). I can get the tampons in, but since the traumatic experience with the other brand, I am TERRIFIED to stand up with one in (I have a chair in my bathroom and a mirror across from it so I can see my vagina if I spread and lift my legs into the chair). I usually put the tampon applicator in my vagina but then get scared and take it out without inserting the tampon. Once I did insert it and was scared to stand up just in case it hurt. Advice?