Can I turn back from this?

Salaam everyone. I've been trying so hard to stick to the straight path, but I feel like it’s backfired on me. A while ago I saw a video about Zabiha Halal meat and got sucked into researching it. I learned that many fast food places, especially here in the U.S., are actually haram. For like six months, I kept it all in and thought it was my duty to warn others. Today, I brought it up during my study circle, and my teacher basically told me I had it wrong. I already knew we can eat food from Christians and Jews without grilling them about how it was prepared. But I didn’t realize that even if the food isn’t from People of the Book, you don’t need to dig for info and make things tough on yourself-like with these fast food joints. Aside from maybe one or two that openly say they’re Christian or Jewish, most don’t. My teacher explained that you can eat from them as long as you say Bismillah and you didn’t already know the meat is haram. But now I do know… basically all the big chains are haram. So my teacher said it’s haram for me to eat there now because I have that knowledge. I get that I shouldn’t have asked. But I thought avoiding the truth was wrong too, which is why I tried to learn. If someone feels what they’re doing is off and runs from the truth, that can’t be right. Now I’ve made Islam harder on myself than it needs to be. If I eat out, I know not to question things. But here’s my problem: is it too late for me to start eating at these places again? What do I do now? Little worried here 😕