How can I create a healthy relationship with him?
With time, great effort and a significant amount of difficulty. Let me emphasize time. He's in a difficult stage right now, and his expectations for a relationship will change as he matures.
What your wife did was illegal and (in my opinion) immoral. And now that he's begun to try out his independence from his mother and step father, it sounds like he's using you to do some of that.
Although in many chances, I tried to approach him, she and her new husband stopped me from making contact with him.
Hindsight is 20/20, but it was at this stage that a lawyer could have helped you maintain a healthier relationship with your son and better boundaries with his mother and her husband. So much could have been different today.
But today is all that you have to work with.
Offer to fly him over to meet you and take a short vacation together where he can spend some quality time with you and some less intense time doing things he may like with you. Use that time partly to explain your absence from his life, partly to get to know him, partly to let him get to know you.
If he really wants a better relationship with you, he'll take you up on it. If all he sees you for is a source of income, he probably won't.
I feel very hurt to see he doesn't see me as a father but only as a source of money.
It's probably nothing compared to the rejection, confusion, loss and other feelings he's had over the years as a result of your absence. It's probably nothing compared to the loss you felt over the years knowing you had a son you couldn't see. Put it into perspective. There's a lot going on here.
Explain (once) your financial situation to him clearly, and make sure he understands it. Then when he asks for things, do what you can/want financially; otherwise just refer to this previous conversation. But don't let your feelings of hurt eclipse this opportunity to build - albeit very slowly - a relationship of sorts with him. Listen to him, ask him questions, give him what is reasonable (maybe consider what you would have spent on him had you stayed involved). If you love your son, then put him first, unless he is toxic to you. If you need help figuring your feelings out, a good therapist is a good start.
This is a difficult situation, but it will pass as he enters adulthood. Consider keeping lines of communication open until then. Good luck.