Come on folks, I think we should give jogging some credit here, because he has pretty much hit the nail on the head.
This is a kind of bragging, and would have made OP's P feel good about himself. Look what I'm doing. Look what I've got. Aren't you jealous. Aren't I virile. Aren't I lucky.
He probably does really love showing off what he's "got". He probably is proud that he gets to have sex with such a desirable body, such an object of desire...
Rather in the manner that some people might show off a new car, or a new house, or some new clothes - things they "have"
Except OP is not a "thing". She is an autonomous human being, with her own thoughts, feelings, rights, emotions, sensibilities.
Fair enough, some people find this sort of thing very titillating and exciting - and WITH THE CONSENT of the person in the video/photo, as a JOINT DECISION - then fine, put it on line and fill your boots, as long as you are mindful of any unpleasant consequences.
The fact is, the OP's P has shown absolutely no consideration whatsoever for her feelings.
She may not be identifiable. That is not the point. She doesn't stop becoming a real person and just become an object just because she is not on film. So she's not identifiable - some might see that as dehumanising her further...
I'm sorry OP, but I truly believe that if your P had really thought you would enjoy your image being shared, he would have had a lovely, sexy time telling you all about it and showing it (and you would have explicitly told him before that it was your biggest fantasy). But he didn't did he? You had to find it by accident.
I don't know you, and I wouldn't dream of telling you to LTB. I know what I would do, but I am not you, and I know you have 18 years of being together and lots of feelings that are going to be hard to shut off.
I would say baby steps. Don't feel you have to make any major decisions now. You have the right to take your time. I would say that you could do with space - and that he needs to see some serious consequences of his actions - whether that's kicking him out for a while, calling the police - whatever - your call - but he can't be left to think that he can do Whatever he likes with no comeback.
If you can bear to tell someone IRL I would. You have absolutely NOTHING to be ashamed of, and it sounds like you could do with some practical support.
I am so sorry this has happened to you. You do not in any way deserve this, and I hope you are able to deal with this in whatever way is right for you 