43 year age difference, meeting a 59 year old when I was 16

I'm an "aspiring" bottom (I'm very nervous so I don't get fucked often, too tight)

I've never felt any physical pleasure, is this normal? I can get the emotional/mental thing, but I don't feel anything physically except slight discomfort.

Can anyone weigh in on this?

Yup! In parks, in forests, on trains, in pub gardens etc. It's a major rush 

I bareback with my husband only pretty much. If we play with other people, we get tested first or use condoms. That's it.