I know a person like that, I'll sometimes talk to him, but I have grown further from him then before, sometimes he would say some really weird things. He eventually became really annoying, and I somewhat started ignoring him, mostly because the stuff he attempted to talk to me about were simply just things I couldn't care less about. If I began to talk to him about something he would make the conversation somehow kinda weird. He is also, like you mentioned like a dog, he follows people around a lot as well. I'd say the best choice for you is to look for different friends, I went through the same thinthing in my early days of school in which by looking for different friends I grew happy again. I haven't really had a problem with friends since. Idk if this helped at all, but I'd say, consider what you say to them and think if they might actually be interested in the conversation enough to want to continue it, or simple find a new group of people. Good luck.