Will it come back again every time I have sex? Or will it go away in time and won't be able to be passed on? If so how long?
Without any treatment to eradicate HSV2, you will have it for life. The recurrences with rash and pain will not be typically predictable, though remaining "stress free" and practicing safe sex so you don't increase your viral load can help a lot. Though the rash or pain is a "clear and obvious sign" that you have active virus; unfortunately, you can also have active virus and not know it, so you have to practice safe sex and use a condom ALL the time.
You can talk to a doctor about taking acyclovir and he or she can further explain how this anti-viral can help you.
For more information, check out these articles:
Genital Herpes: The Basics
The Truth About HSV1, HSV2 and Oral Sex
Genital Herpes Symptoms and Tests
Ways Not To Spread Herpes
Symptoms Of Untreated Herpes