The weapons which we received were in return of releasing U.S hostages, people call it ransom, but you are free to call it help! whatever else we bought has been through middlemen and is the reason U.S destroyed his own fighters along with it's factories.
No, U.S didn't attack ISIS before Iranian backed forces started annihilating them in 2015.
what we gave Houthis was the know-how and sensitive parts, not a complete package, if that missile isn't similar to ours, it's not similar to any other country as well, but perhaps you think U.S has developed a Qiam like missile and an Ababil-2 like drone as well!
The U.S. attacked ISIS in 2014.