Three months isn’t a lot of time, so I would talk to a lawyer sooner rather than later. Google employment lawyers in your area, or “attorney referral service [your state].” You should be able to get a free consultation.
Some lawyers may be able to tell you right away if they’ll take your case, but it may take a little time. And you may want to get more than one opinion. If you have any documents, round those up and hang onto them.
Good posture also helps you breathe better, which can help you feel more energized and concentrate better. Your diaphragm doesn’t work right when you sit hunched over, so your breath gets more shallow.
If you ever need to talk a lot for work or some other reason, good posture is essential so your voice sounds good and doesn’t get tired too easily.
And it helps strengthen your core, which is good for balance and other things.