hmm...don't make a fool out of your current girlfriend! Making her believe that you love her while secretly cherishing another girl is totally unjust. Only heartless people can do such sadistic thing. I suggest you tell her the truth (don't make up various sorts of silly reasonings like "I want to focus on my studies", "my parents doesn't approve of you" etc.) to further and to quickly asses the problem. If you really don't love her, set her free. You can't have the best of both worlds, playing safe like a coward, making her your last resort.
In regards on that eced girl, meanwhile, why didn't you courted her before? Before all of this mumbo-jumbo took place? If it's your lack of guts that made her unreachable for you, well...that's a very hard thing. You must to muster it all, my friend. Just remember, with faith and hardwork, we can sow the goodness of our toiling.
Your Friend,
Princess