You should definitely say something either to him or someone superior. That's not right for him to play w/ your grade like that. It was his mistake.

Similar thing happened to me but the teacher was nice enough to up my grade, I would talk to your academic advisor about it

Don't accept that as an answer. You were the responsible one hear, you didn't just use the source while being unsure about it, you consulted the teacher and had it confirmed. That's what most teachers recommend if you're uncertain about a source. Go higher up and ensure you don't get docked for this, him being wrong and giving inaccurate information is what caused the mistake, it was not an error on your part, so therefore the loss of grade is on him, not you. This will be a lot easier too since you have the email as evidence.

this happened to me but my mom went to the els teacher because I have an iep and it got fixed

I swear they will let anyone teach these days

"I guess you were wrong about my grade too then."

I have a history degree so I think I can help. A primary source is from the time but has no hindsight. E.G. Eyewitness account, newspaper article. A secondary source can be from the time, or after it. The main difference is that it has hindsight. E.G. A newspaper written a day or two later, a memoir written by an eyewitness. A tertiary source (sometimes referred to as a secondary source in school) is a source that is both a primary source, and a secondary source. I.E. It's a primary source with some analysis. A memoir would also be tertiary if the writer reflected on how it impacted their life. Textbooks are also tertiary sources. Hope that helps.

In a way, primary sources are easy to figure out. Did it come directly from the person, place, or was it made when the event was happening.

If he doesn't change your mark, I would petition that.

Then you go over his head (to the principal, department head, whatever), explain what happened, and get the grade changed