So scared to get pregnant

My fiancé and I have been trying for 4 years. We have unexplainable infertility thus far. All tests have shown there's really no reason we aren't getting pregnant. I have one more test to get done - I can't remember what it's called but it's some sort of imaging of my Fallopian tubes to make sure they aren't blocked. If that comes back ok, then our doctor says we can do insemination. If not, we have to do <a href="https://glowing.com/glow-fertility-program">ivf</a>...either way the more I think about it, the more I question wanting to be a parent, which is absolutely crazy because I can't tell you how much crying, begging, pleading and heart break I have gone through month after month of negative tests. We've done everything we possibly could think of on our own. I've been jealous, bitter, all of the above. And now? Now I don't know. Bringing a baby into this world scares the hell out of me and so does being pregnant. I'm afraid of morning sickness, birth, how those things may effect my job, all the expenses that come with children, etc. I just don't get why I'm all of a sudden feeling this way after so many years of trying so hard. Maybe because it's becoming more of a reality if we start treatments...I don't know. Has anyone else ever felt this way? :(