Trust is a hard thing to come by in EVE.
You have to more or less forget everything you know about online game players in general and think that everyone is out to get you for their own personal gain. You will find so many people that are looking to scam you,steal from you,trick you to get a km, just wants to make a young player angry, spy on you and in general just make your life miserable and seek your complete and utter destruction.
From what you have been saying so far im guessing your a former WOW player.. One of the major differenses is that in WOW you can just change servers if you do something to damage your reputation. In EVE the only real way to get rid of your reputation is to start a brand new character. This is why you need to consider what direction you want to go in very carefully. Do you want to be the low life pirate that gets his enjoyment out of stealing from noobs (similar to what you exsperiensed),or do you want to be a pirate that actually fights people who can fight back,or do you want to create your self a reputation as a major industrialist? There are so many options...
But anyway the point is.. The guy who "helped you out" is most likely just an alt and teh character will be deleted soon enough. If it is a player you can make it a goal to one day hunt him down and make HIS life miserable
Just keep in mind that you can never fully trust anyone in EVE,not your long term friend,not someone you even consider as close as your real life friendsnot your CEO and not your directors. Anyone in EVE is capable of (and most likely will) do something that you consider backstabbing at one point or another and if your not prepared for this it will be mentally rough.
This dosent mean that everyone is bad. It just means that you should always expect the worst. As you play you will notice that people will feel the exact same way about you; Is this guy a spy? Is he a corp thief? Is he looking to join to blow up corp members for fun? Will he cause trouble?
Dont take it personal when people seem to act cold towards you. You will have a lot of trouble getting anywhere in EVE unless you have a certain level of paranoia
Pick your corp carefully,pick your friends even more carefully and never ever trust anyone. If you keep that in mind,learn from the times you get scammed and robbed or betrayed you will do fine.
Welcome to EVE and i wish you the best of luck out there