I'm 17 and in a romantic relationship with a 40 year old. What should I do?

This question is for those who won't judge my relationship... If you feel you have to say something rude. Don't bother commenting.
Anyways... He's not a bad guy. At all... Originally i lied about my age and told him I was 18. Then eventually told him I was actually 17. He began to text me less and act a bit more different... More reserved so to speak and eventually he said he's willing to continue this but he has to protect himself. I look nothing like a child... I could pass for 20 if I could. The issue i have is im fustrated... I want to be with him but at the same time I'm scared of beong with him. If I leave i won't ever find a guy like him... If I stay... He most likely will die earlier than I want him to and hes a very active risk taking guy. I still would very much like to be in his life even if hes not my bf but what 40 year old wants to have a friendship with a 17 year old. He can barely text me. I doubt he'd want to ever meet again... I love him so much. You have no idea. :/ his intentions with me were never sexual... He flirted a bit when he thought I was 18 and then completely stopped that and just conversed with me after finding out I'm 17. I just don't know what to do or how to feel anymore. We met once and I want to meet him again... At his place. Not for sex. I want to know him deeper and have a closer relationship. Hes not a pedophile. Hes not a bad guy.