Whenever one goes through some difficulties and then succeedes, our brain rewards us with endorphines, the neuropaths supporting this activity are strengthened, the unpleasant memories are easily suppressed while the reward is associated with the activity. Normally, this is very benevicial because this is what makes people enjoy activities such as physical exercises. Students who learn very hard for their first exam and then receive a good mark are motivated to study for the next exams too. Etc.
In your case, however, this feature of our psyche has been exploited by a person who cares nothing about ethics. First, you were told to empty your bank account. Definitely, this was not very good experience, but afterwards you masturbated and as a consequence the mechanism I wrote in the previous paragraph was activated very powerfuly.
What can you expect from now on? First, you will be aroused when you think about repeating this experience. Then you will look at the respective site. Then you will contact again the person. And then you will give the person your money again (unless this person is unexperienced and doesn't know how to deal with your fears and how to exploit your weakness).
What can you do about this? Well, first of all, you should analyse yourself in order to realise very clearly that your psyche (just like the psyche of any human) is a jumble of very different and contradicting thoughts, wants and likings. Don't be deceived by things like 'Hey, this is what you want'. There is no such thing 'what you want'. There are many things you want. Yes, you want to go again to this hypnodome and yes - whatever you do, you will probably want this for a very long time. But at the same time you don't want to go to this hypnodome. Therefore, it doesn't realy matter what you want, what matters is what you choose.
If you chose not to go along this selfdestructive path, then don't! And be very determined about this! Inevitably, there will be periods when you will "forget" about your decision, but when you become aware, you should renew the promise you made to yourself. It doesn't matter if you have broken this promise so many times! Don't go to this person again. Never. Don't think about him. Period. You will fall but then rise and never doubt that you will succeed!
Very soon you will feel the positive changes in yourself. Yes, you will be tortured by the desire to do the stupid thing again, but nevertheless, the quality of your life will improve and you will be perfectly aware about this change.
And finaly and very importantly: be sure that the temptations you are fighting will subside with time – after about 2 months if the addiction was formed when you was older or 4 months in the worst case if you became addicted in youg age and didn'f fight the addiction for a while. If you want to know more about the mechanisms of your addiction and why it will disappear (inevitably!) after a while, search the net for 'ΔFosB'.
Also, if you have a girlfriend, then you should realy love her and it will be much much easier.