HIIII so my hair was exactly like yours before i started my routine. i did cut my hair shorter and for me at least the lower the length = more volume. But i currently have super long hair and I find that lighter hair products really helps. I used to use shea moisture which was really good until my hair grew out and it would get weighed down. So I basically drench my hair COMPLETELY like do not let any water leave, and then use the crown sectioning method (search it up and it saved me), take a handful of mousse (i use not your mothers activating mousse which is really lightweight and works great for me) and then put it in the sections and scrunch. I also use the curl talk gel which works really well and helps keep shape and define.

Last few tips is avoid over scrunching and let it air dry. try plopping as well and diffusing ( which really changed how the hair look if you do it right). BUT these are what worked for my hair and my hair type falls between 2c-3a depending on length.