masturbation has always been a struggle for me

Masturbation has allways been a struggle with me because of sensitivity or sometimes lack of sense you see I have sensory processing disorder and guess what it effects your sex life as well I am ftm ( female to male) and inside penetration does not do it for me I can’t get off that way the only way I can get there is by jerking it and that’s all fine till you become less sensitive after a while any advice? If this is in the wrong place please let me know