Aw511,
My heart is truly breaking for you. I understand how much pain you must be in. You have had quite a blow to the head with his going straight to a dating website.
You would think that he could respect the relationship that you had for at least a little while. My ex didnt even bother to say goodbye. When I said I couldnt take it anymore, he erased me without a word. He was tweeting promiscuous things to a girl he had met online within a few days of our breaking up.
Your ex going straight to dating shows you what type of a person he is.
It is not possible to love someone and get over them in a few days time. He did not love you the way you loved him, and now he NEEDS someone else to calm his pain.
People with BPD can not soothe their own emotions and must do it through other people. They have to have someone to cast their pain on to, or they will emotionally bleed to death.
My ex use to post songs on his facebook when he was trying to lure me back, the problem is, I saw on another website that he had linked that very song, that very night to someone else... .He was fishing and hoping to reel one in. Maybe he wold prefer one to the other, but either will do in a pinch.
The sentimental picture is your ex going fishing He is trying to invoke your honest and loving feelings for him. Your honest and loving feelings are PRECIOUS and there can be no value assigned to him. No price can be paid to obtain them. So he wants you to sell them for a picture? Pfft. You are worth more than that.
It is his loss hun... .YOU must love yourself enough to keep his crap out of your life. Keep going strong and moving on.

You can do this!