Thanks for the advice guys.

Actually learning 한글 is extremely easy to learn. You can learn the whole set of characters in an hour or so. I imagine you are not spending enough time. As the other members have told you, the only way to memorise them is by practising them. But I do not agree with Aria. Romanising a text is the worst thing you can do. Try to understand what a text says in 한글.

Agree with David, just read hangul text then try to romanize all the text.

u only need more practise of memory,,, is very easy,,, i speak spanish but i memorized all the 한글 alphabet :D... u can practise reading korean texts or sometimes trying to write ur own language in 한글, for example 올라(Hola{Hello in spanish}). This kind of exercises i used to learn the alphabet very fast. Greetings!