I feel it wise not to fall in the Watchtower trap of ever thinking we have "the truth". I live my life using evidence presented to me, if something better comes along I'll consider it and if it works go with it. My worldview is basically a model I use to navigate through the world around me.
This idea that we need to know "the truth" is the reason we have religion in the first place. Bronze age man see's a rainbow and so believes a man in the sky put it there as a promise not to bring a flood.
Now that we know about light particles being refracted through water vapor the bronze age explanation sounds like something a child would say, yet 8 million JWs actually believe the rainbow story.
Rather than worrying about what we believe, try to be comfortable with the fact that you will go on learning everyday. In 10 years we'll probably look back on today and laugh at some of the things we once thought. Especially medically. But this is actually a wonderful thing - not being content with "just believing" something, if we keep testing, questioning and trying we'll keep discovering new things.