We all have that one friend who can't stand to be alone. We also all know someone who cumulates relationship after relationship in order to fill a void or to forget the rejection from someone whom she liked.
I mean this rebound isn't necessarily attractive (in your book), the important thing here is that this person is crazy about you. It boots your confidence, fill the void and gives you power in this relationship: thing you didn't have in your previous one and the reason why you ended up with your heart broken in a thousand pieces. It's an ephemeral relationship that will keep you busy for awhile.
When you had the flu, it's good to drink Gatorade because it'd give you the energy you need. When you're dealing with a mono, you need to rest and don't do any physical activities. When you have a broken leg, you can go on a long walk. These are 3 examples that all make sense, and evidently, you were already aware of those. Apply this same method on breakups. You'd tell me how you'd put a band-aid on your injury where there's blood and let's just say that your rebound is your band-aid. I'll just say how there is no miracle solution to deal with a breakup and how a band-aid will only keep the pain temporarily away. It'll come back eventually. How will you heal shall you ask me? Time heals… it's as simple as that. There aren't any banana syrups that exist again grieving.
If you feel you can't deal with a breakup, don't jump on a sinking ship. Just bear with your vulnerability and be the bigger guy. In my opinion, it would be low to use someone who cares about you only to take care of you own tormented eg. There's nothing great in the notion of using a human being like an object that will only be thrown out in the trash once you're done patching up your void with his affection.
Sorry if I'm being rude, but it's unfair to go after a stouthearted man in favor of the heartbreak your previous partner has caused you. It's even sadder when we see that you would be ready for anyone as long as the latter has an interest in you since the one you want doesn't feel the same about you… desperation to its finest.
I remember when I was 7 years old and my mom would get mad at me before I'd drag my feet as I was walking. She would always tell me how I shouldn't eat with my mouth open and to sit straight when we were eating at the table. She also taught me how to treat people the same way as I wanted to be treated.