Firstly very sorry for your loss 
With him for starters I NEVER add anyone on sm I don't know well in person
For another - before you've even BEEN on a date with this guy he's PROVEN he WON'T take no for an answer - not someone I would want to risk being alone with!
And for another what he's done is creepy, manipulative and seriously crosses normal boundaries!
Tell him to destroy the seriously inappropriate pictures, BLOCK and have nothing more to do with him and learn to control your sm properly and how to stop being such a people pleaser, "no I don't want to date you" is a perfectly acceptable and suffice response to being asked on a date.
Your friend is right! Knowing she thought that why on earth did you add him?!
I hope I'm not being too harsh.
You NEED to be harsh with people like this! They don't get it otherwise!
You give this guy the SLIGHTEST hint he can wear you down you'll never get rid!
"I did NOT give permission for you to use those pictures, destroy them you do not own the copyright, I am NOT interested in dating or even being friends with you and I am NOT interested in having any more to do with you. Leave me alone!"
Then block, tell your friend you've blocked him and that you don't want her or her boyfriend telling him ANYTHING about you - your life is none of his business!
You seriously need to work on your assertiveness and confidence.