It is good that you know she will be replaced by another girl in
the future. So basically, you know that the main solution is time.
How long? Up to you.
This jealousy feeling of yours is normal. Cause you are still very
much in love with you. Or should I say, you still can't let go of
her. But there is one thing you have to know, she no longer bears
any feeling for you. This is the cold hard truth. Sorry mate, you
just have to accept. The fact that she has found herself another
guy, and is very happy with him says all.
Firstly, you have to
accept the fact. Know that she no longer likes you. And for this
very moment, no matter what you do, she is just not going to go
back to you. Anything else, she will probably find you irritating
and it may worsen any possible happenings in the future. That is if
there is any...
You have to leave her alone now, if you have to listen to her, know
what and how she is doing, drop her a few sms over a few days.
Let's say, maybe once or twice a week?
Secondly, avoid
trying to know too much about her life right now. Avoid asking
questions about her and her new guy. In short, just try to avoid
her. Try not to go back to the usual haunts that you and her been
to, and avoid doing things that can possibly remind you of her.
Discard everything and anything she gave you. If you can't bear to
throw them away, gather them in a box and keep it out of your
sight.
Whenever you know she is going to take over your mind again, stop
yourself. Tell yourself that she is happy right now, with another
guy. She no longer needs you. Everything she once said to you, once
did with you is already history.
Treat this as a lesson
in your life. Like you said, you are going into the army soon.
Don't take this burden into it. Take this as an opportunity to
learn more things, make new friends, and reflect on yourself. Tell
yourself what have you gain, and what have you lost. Reflect on
your weaknesses and try to improve them. Make yourself a better man
that you, yourself can be proud of.
So relax man. I know it's always the same thing that everyone have
told you, but it's really time. Do not bear false hopes that she
may return to you, in the near future or whatsoever, cause all
these, are merely illusions.
Let nature takes its course, take things in your stride. Actually,
if you can... chop off all ties with her. What's yours will be
yours, what's not will never be. Leave everything to fate
man.