Run that by me again. Did you say that they were bothered by the Topik, and told you not to use it? If not, it sounds to me like they are bothered you don't hang out with them during the day, and they know it is because of your hair, and maybe one time when they were talking about your insecurity, the mensioned the topik.
Your hair loss is not ending your friendship. You are. I'd be more convinced if you said your hair loss drove your girlfriend away. But even that is not a definite, especially with your NW2 pics I saw. Going from NW1 to 3 fast will probably get you dumped with most women, but if a woman took you at Norwood 1.5, she is not going to dump you if you go to Norwood 2.5. Put on a hat and go invite your friends out somewhere fun. They are NOT gone for good. And if you go without the hat for one day, you can impress them. But if you know you will freak out, just where the hat, since you do not want them to see you freak out.
Another way your looks can affect a friendship is if they get prettier women than you, and your girlfriend wishes she could have one of your friends, and you are jelous of your friends, you don't take the women you can get and are jelous of your friends. But as long as you act happy arond them and their success, and act like your old self, they are not going to leave you because your looks fade, and will spit on any woman who asks them to not invite you somewhere because of your looks.
And just so everyone knows, Topik is good only if it matches your hair color very well. They don't have my color, and I don't want to die my hair to match it, and I think most dies don't look natural. It would be nice if there were a thickening hair gel, so no women would touch the hair and discover it, like Topik. Gel is still acceptable.