Trading or training? I get the sense that you want to keep your drifloon (as you mention overcoming your fear of it), but then again, you may be asking how best to rehome it in order to alleviate your fears in an entirely different way.
So allow me to answer both questions separately.
If you mean training, the key here is trust. Remember that the pokédex is largely a generalization; while it indeed describes the most common behaviors of a species (usually), species are often complex, with members who might not fit the “standard” description. It would be like assuming all humans act in a very particular way.
That having been said, it’s important to get to know your drifloon. The only way to do this, however, is through training: the more time you spend with a pokémon, the more you begin to understand its needs, interests, and personality. That and you’ll naturally begin to train yourself out of your fear of drifloon via exposure therapy. So my advice is simply keep training it and spend more time with it. Eventually, you’ll alleviate your fear naturally.
If you mean trading, you have two options. The first is giving your drifloon up to a shelter and allowing them to find a good trainer for it. The second is using a trading network like the GTS to find a trainer who specifically wants a drifloon. (Many type specialists use the GTS in this manner, so you may have a good chance of finding someone who already knows about drifloon’s quirks and is prepared to offer good care.) Either way, be sure to talk to your drifloon first and reassure it that the reason you need to rehome it isn’t because of something it did but rather because you can’t give it the care it needs. Such a talk will make the trade less traumatic for it.
Best of luck!
The Pokédex According to Bill 