How screwed am I?

It happens, you're fine. Honestly I remove those first node branches(sometimes the 2nd too)anyway as they tend to grow stretchy with large gaps between nodes. When using LST, take baby steps when working with stems that are starting to stiffen up.

don't worry bro its a weed.

If it is an autoflwoer, it's permenant loss. With a photoperiod it just costs you a little extra vege time to regain what was lost. Some plants are more maleable than others (genetics).. sometimes it is indicative of a slight imbalance of fertilizer if the branches are brittle early on -- they all get rigid over time but should be bendable early. You get lulled by the easily trained plants and then all of a sudden you snap two branches. that shit happens. I did it twice to the same plant last grow cycle, lol. "1" plant just wasn't as pliable as the others mid-flower. It ain't growing back mid-to-late flower, lol.

They will respond to it well don’t wo

It’s not terrible for the plant. I mean it’s probably pissed, but it will live. I would leave her be to recover for about a week though for sure. Topping and then dismembering her is probably enough for the time being lol