I’m a beginner sissy and I wanna do sissigasm 🤭

Hey , Im 20 years old , Im athlete, but since 3 years ago I used to watch some gay stuff and dicks and cucks , actually I like it,like 2 months ago I bought dildo , chastity, plug and vibarator , and female underwear, Im using it but it’s hard for me to reach sissigasm, I wanna do it while wearing chastity with free hands , I had some precum while wearing it , and while fucking my self too , but I still don’t know how to really cum, I also feel in pain while wearing chastity and getting hard , also while fucking myself , and I really need help guys 🥹💕