Alright, enough insults and here's some actual advice.
MH is an action game, but it's not a fast paced action game.
People suggested it to you presenting it as an RPG instead of a simple action game, for good reason.
MH isn't "clunky", instead it locks you into it's iron clad pacing and expects you to adapt, not the other way around, when you first approach MH you must enter the mindset of a student, and the game is the teacher, he's showing you something new that you aren't accustomed to, so you must learn.
In order to facilitate the learning process the game (especially the newer games, 4U, Gen for example) will give you a shit ton of tutorials so you can familiarize yourself with each weapon and all the systems.
Additionally, at the start it will SHOWER you with gathering quests to make sure you're running around exploring and not getting immediately thrown under the bus hunting something too dangerous and quick for you yet.
In MH, each time you attack you're committing yourself to the attack, every single animation is slow and deliberate on purpose, if you press that button, you're committing to that action.
At the same time, depending on your weapon, tons of animations can be cancelled into a roll or some other attack, this is the basis of your mobility.
The other key element is positioning.
In your average action game you will approach something, and attack, in MH, you must approach something, position yourself in the right spot where you will want to hit in the near future, and then attack, attacking is a sort of quick, short term plan you must do in your head each time, just like you would plan out a sequence of actions in an RPG.
The bottomline is: everyone was shit at MH when they first started out, it's expected of you to be utter shit at it.
The difference is between people that give up, and people that toughen up the initial rough hurdle, and then get gud.
MH is a game of perseverance and force of will.