It is quite right that you should feel that 'something terrific' has happened to you. Accept these sensations with thankfulness as birthday cards from God, but remember that they are only greetings, not the real gift. The real gift is the gift of the Holy Spirit.
The sensations are merely the response of your nervous system. Don't depend on them. Otherwise when they go and you are once more emotionally flat, you might think that the real thing had gone too. But it won't. It will be there when you can't feel it. May even be most operative when you can feel it least.
This is the push to start you off on your first bicycle: you'll be left to lots of dogged pedaling later on. And no need to feel depressed about it either. It will be good for your spiritual leg muscles. So enjoy the push while it lasts, but enjoy it as a treat, not as something normal. He will still be there, even when you can't feel it.

Some thoughts by C.S. Lewis, from a letter to a friend who had just found Jesus: