I injured my knee a month and a half ago and have been unable to work or receive care due to not having insurance. two days ago my knee gave out twice?

Uncertain: It may have given out because of pain or instability. Don't know where you live, but many communities have clinics with sliding scales and some where treatment is at no cost.

Be seen: Most towns, even small towns have indigent care programs where people with no or little insurance can receive the care they need. You can usually check directly with your hospital to see if you are a candidate. It should likely you may have some form of internal derangement of your knee which usually involves a tear in a ligament or meniscus in your knee. There are other possibilities as well.