Your employer may have violated your legal rights in the workplace. Remedies may exist. But these remedies may be complex and hard to obtain without a lawyer on your side. There are time limits on your exercise of these rights. If you wait too long, and in some cases that may be a very short time, you will lose your rights. Further, in order to present a case in court, you may need to “exhaust” remedies by filing with state or federal agencies first. There are time limits to file with an agency, and more time limits if the agency does not give you what you want but instead gives you a “right to sue” notice. If you are a public employee you may have to go through your agency's processes first, or, in some cases you may need to bypass those remedies if you want to get your case heard in a more neutral court.
Many laws, say, involving leave for illnesses and disabilities, may apply to the same situation, but have different requirements and different remedies. Only a qualified lawyer can sort these out and explain your rights to you.
Some problems may be worked out without going to court at all, but it is helpful to have a lawyer to guide you or, perhaps, to contact your employer directly to attempt to work something out.
To sum up: it is helpful to have a lawyer guiding you through workplace difficulties, or at least consult with one to see if anything can be done.
Here is some additional information you may find useful: