I was under the impression that since our company is a pass through LLC, I would just file my regular federal and state taxes like I used to file when I lived in the US. I am not sure which state I should file the taxes in now. Also, we received a notice from IRS stating that we need to file Form 8804 and 8805 - when I read this up on the IRS website, it seems like IRS is asking the company to withhold 37% of my income in taxes.
You are going to file as a non-resident. Since you don't live in the US anymore and you are not a citizen you can't file the same way that you did when you lived here.
TurboTax doesn't file non-resident returns. For that we partner with Sprintax. Here is a link.
The partnership is required to withhold taxes if it has a non-resident alien as a partner. That is why the forms are required. On the upside it means that your taxes will already be paid when you file the US return.