Hi, Phoenix.
I am able to speak 6 languages.
One of them-Italian, I tried to learn by myself. This led to that I know it the worst. I remember just some grammar rules and some vocabulary words.I can understand Italian well,but if someone asks me..No, I answer him/her, but it would be very slowly and with the help of gestures.
I would like to advise you not to torture yourself, but to find a very professional teacher, who WILL NOT speak with you in your native language, but JUST IN GREEK! exclusively!!
This is the best and the shortest way to learn Greek.
And study that kind of Greek, which is mostly used by Greek population.
Cheers!