Since it is your own fault, you should be honest and lenient. It should be said like this:
Hello, we have only seen each other for several years. I still remember your profile picture from back then. Unfortunately, things have taken a toll on people, and I suddenly forgot ‘what’s your name’? Time is ruthless, but people are affectionate. I know I can't keep you, but I want to keep your name. Whenever I think of you and know your name, I know you as a person. Look at the chat history, browse the space, check Weibo, and look for your shadow. Do you agree?