I'll shoot.
It sounds like this guy has "puppy dog syndrome". (I made that up but I hope you get it.)
He hangs around like a puppy dog looking for a master. In other words, this guy has not thought that he could do better for himself so he holds on to the one thing he thinks he still has. And maybe he does on one level, but wont on others. He is going to spend his time hoping you change and is so "unshallow" that he is willing to wait until you get over your "slump". The problem is that he cant change a person. Accepting people with the hope they will change is wrong.
For whatever the reasons, you are who you are. And there is nothing wrong with being alone, as long as you are honest with yourself about it.
So, he needs to hear from you that things are not going to get better. This is it. This is as good as it gets with the potential to get worse. And that you could not give him what he wants and he is wasting his time.
Now, he may think he is in love. So the best cheesy line to use is, "If you love someone, let them go."
Or "You want me to be happy? I am happy alone."
Other than that, this guy sounds like a loser. No offense, but he does sound pathetic. Mostly because he just doesnt get it.
Good luck and I hope it works out for the better.