Accidentally used all of the "starter called the "seed" instead of half of it for barm

So long as you have an active starter, you didn't do anything devastating. You will just have a barm that likely eats up all the available food a bit quicker than it would have otherwise, and probably a little more alcohol than it would like. You can simply let it sit for the 12 hours or so, and then divide and feed as you would otherwise, It would be fine to use to bake sourdough bread with. Sourdough starters generally take some abuse before they give up the ghost entirely. When in doubt, just toss half and feed the rest, give it 12 hours to recuperate, and check it. It should have doubled itself in size, and fallen, and be good to go to baking.