When is it safe for me to assume I have no more lice?

I had been itching for about 2 weeks, had my mom and boyfriend check me and they said I was clean. 🤔 But yesterday morning in the shower I found a fully grown louse on my shoulder. I am 24 and hadn’t had them since I was maybe 7 years old. I had a huge panic attack because

1) I am a performer and am currently running a show for the next 2 weeks nonstop every night, which means I have to conceal this from my costars + make sure my costume is washed which isn’t totally up to me. 😭 and

2) I have thigh length (yes thigh length!) 2C thick hair. I immediately ran to the store and bought the Nix kit and tea tree oil.

I combed through my hair with the lice comb for 3 hours with no breaks and got a lot of lice out especially newborn tiny ones. I got a good amount of eggs too.

Then I did the Nix shampoo treatment and my boyfriend helped me wash my hair out. Combed again for another hour and found a few more but it was way less. Had to get ready for my performance of the night so I mixed my hair gel with tea tree oil. Got home, showered, and stayed up til 3am combing again but only found one dead baby louse. Smothered my hair in the oil for the night, woke up and did the treatment a second a time, no lice fell out. I have combed for about 3 hours now and have only found 1 egg about 2 hours ago. My scalp is kind of sore and bloody at this point.

Is there anything else I should do? I have washed and sanitized my bedding and clothing and my boyfriend is staying at his grandparents now because he has them too. We decided to stay apart until we are both 100% lice free.

It should be mentioned my hair is long because I am Native American and while I’m not totally opposed to cutting it my family would definitely be upset with me + I wouldn’t be able to cut it too short.