OK, so step 1 - till she goes, you should not be in contact with her at all - even if something terrible happens to her, and she needs someone to talk to...no mater what.
Now, in Israel - first of all, you'd be amazed at what can happen. Now, if you "might" have forbidden thoughts, how can that be the basis of a positive relationship - if things do work out between you two, don't you want to start off in a good way?
As far as general friendships with girls, I personally think it's a dangerous situation, but for me in particular, it was bad, because in my community, guys and girls aren't usually friends, so for me, it was a secret friendship - so, not healthy. my point was that when a relationship isn't healthy, it needs to end.
You say that you want the same things in life. That may be - but she's about to go to israel for seminary, and many times, people change their minds about what they want, what their priorities are, how they see things, etc. It may be that at the end of the year, after each of you growing, you'll be even better suited for each other - but if you stay in touch, it's likely that you'll each hold each other back, because you WANT to stay on the same page. And that may end up costing both of you significant growth.
Let her go. If it's meant to be, it'll happen - but you need to move on. Right now, this isn't healthy, and you need to get far, far away from it.