I'm in Texas, and you can collect severance and unemployment at the same time here. However, I do not think you can apply until your actual termination date (March 1st for most of us), since you are employed until then.
Retirement is not a factor, you can't be forced to retire. Even if you are collecting Social Security, you are entitled to at least some unemployment benefits in most states.
Start researching your sown tate's requirements right away. Good luck!