Although the Americans With Disabilites Act can protect employees against being terminated due to having completed or being enrolled in rehabilitation treatment for drug or alcohol addiction, it does not protect against being terminated for current drug use. It is not likely you could bring a claim under the scenario you described.
Being able to successfully bring a legal claim against an employer for wrongful termination usually involves more than simply being able to prove that you did not do anything wrong. Wrongful termination is a generic term that refers to any termination that can result in legal action against the employer. Although the laws are different from state to state, generally there are several different types or varieties of wrongful termination claims. Your rights as an employee depend on several things. One, whether you have a contract of employment and, if so, whether the employer violated the contract. Two, whether you are in a union, and if so, whether the union agreement was violated by the employer. Three, whether you are a government or civil service employee protected by civil service or other government laws or regulations, and, if so, whether the employer violated those laws or regulations. And four, in addition to the above (or if none of the above apply and you are an at will employee), whether the employer had some legally prohibited motive or reason for the termination. Most of the illegal or improper reasons for termination are exceptions to the at will doctrine and they require proof of some illegal or improper motive such as discrimination due to your age, race, sex, color, national origin, pregnancy or disability. Some exceptions require proof of a retaliatory motive such as retaliation for complaining about illegal conduct of the employer like not paying overtime, or violating OSHA regulations, or discrimination, or taking FMLA leave, or filing a workers comp claim, or doing other things that the law either gives you a specific right to do or imposes an obligation to do.
If you want to determine if your rights have been violated as an employee your best course of action is to speak to an employment lawyer and be prepared to discuss the possible motives for the adverse employment action. The question of how long you have to file a claim depends on which one of the possible claims you may have.
Disclaimer: This answer is provided as a public service and as a general response to a general question, it is not meant, and should not be relied upon as specific legal advice, nor does it create an attorney-client relationship.
My name is Walter Kane. I am a lawyer and medical doctor in Texas. I am sorry that you were fired from work, and that you have had to fight with alcohol and drug addiction. It is upsetting to hear that your boss did not offer help when you confided to her that you had this problem. To properly answer your question an attorney would have to know more details of your medical history, your company's employment policy, the terms of your employment contract, and more information about the circumstances of you getting fired. The best thing to do is make a time line of events. Gather all the information related to your employment and make an appointment with a qualified employment law attorney.
Dr. Walter Kane M.D., J.D.
Kane Varghese Law Firm