I'm too young to have this issue... HELP

Ta
I've been sexually active since I was 12 (not by choice the first few times then by choice around 14-15 years old) and I've always been just kinda... eh with sex; I don't crave it and I never really have but now I have almost no sex drive at all which is a problem. 
I could honestly go a year without sex and it not bother me but that's not feasible when you're in a relationship unless that person is the same way.
I've been married for 2 years this August but I'm a relationship with my husband for 5 years in October. I love my husband, I'm attracted to him but I have no sex drive and that's not fair to him. I've told my doctors, my therapists, pretty much all the medical professionals in my life and had blood tests done, prescribed for my depression on different meds to see if being on certain ones was making it worse and no one can figure it out.. 
I'm only 21, I love sex itself, I love sex with my husband, I just don't care to have it and getting in the mood mentally can get difficult for me. 
We've even gotten into the more kinkiest stuff like BDSM that we absolutely love but this is still an issue with me.
Has anyone else delt with this and/or can someone maybe give me some advice or tips?
I want my sex drive back 😭
It started strong and now I feel like I've lost that part of myself overtime; it hasn't caused problems with our marriage yet but I don't want to give it the chance to get bad enough to start causing issues.
 I've actually told him I'd be willing to let him do it with others if I get bad enough because I don't want to starve him if sex and I guess to me if I know it's happening and it's nothing but sex, it's not cheating but he doesn't like the idea and says he would rather not have sex than do something like that but I don't want to put him through a marriage with little to no sex. 
Oh, I've also never had an orgasm with anyone or by myself, almost think I can't but it's not important to me when I'm actually in the mood.