Are you an agnostic or a Wiccan or Buddhist if you believe in reincarnation and God and heaven and hell and mother nature but do not think Jesus was the Son of God?

Answer

Wicca and Buddhism are not remotely related to Christianity. If you believe in the principles of Christianity excepting the divinity of Jesus, then you're closer to Judaism than you might think.

I might also suggest research into Gnostic Christianity, which was an early schismatic sect that was promptly stamped out as heretical by the Church fathers.

Also, if you believe in reincarnation and God, you are certainly not agnostic. It is possible for a Buddhist to believe in the Abrahamic God.

 

Answer

Actually, not believing in something and/or believing in another does not make you part of a religion or cult automatically. You have to make a conscious choice to be part of a religion.
To the first answer, Gnosticism is far older than Christianity. Gnostic Christianity is only an adaptation of Gnostic ideas into the Christian main body of theology. This Christian Gnostics (Which by the way is a self-contradiction) appeared (or at least their writings did) at the very earliest circa 150 AD, but most scholars think that circa 200-250 AD is more accurate.  

Answer

First, while it generally does refer to a basic belief in "god" in some form or fashion, "Agnostic" doesn't refer to a specific religion. Instead, it generally refers to the belief that the ultimate truths of our existence are unknowable, and that basically all religions are flawed in one way or another. This is different from the term "gnostic". As such, you could be considered agnostic.
Wicca and Buddhism refer to specific religious theologies which would depend on your other specific beliefs. Lack of faith in Jesus Christ simply means you wouldn't be Christian.

Answer

You're not an agnostic because you believe in God. You're not a wiccan because wiccans don't believe in heaven or hell. You're not a Buddhist because Buddhists don't believe in God. Hindus believe in reincarnation. They believe in a God. They believe in heaven and hell, but they are not eternal heaven or hell. Eventually you get out of both of them and go back to mundane life. Hindus have a great regard for Nature. Hindus do not think Jesus was the Son of God. Maybe you've been a Hindu all this time and didn't know it. Hindus worship in temples called mandirs. If you can find one, you may find people there who share many of your beliefs.