The Age Discrimination Act of 1975 prohibits discrimination on the basis of age in programs and activities receiving federal financial assistance. The Act, which applies to all ages, permits the use of certain age distinctions and factors other than age that meet the Act's requirements. The Age Discrimination Act is enforced by the Civil Rights Center.
The Age Discrimination in Employment Act of 1967 (ADEA) protects certain applicants and employees 40 years of age and older from discrimination on the basis of age in hiring, promotion, discharge, compensation, or terms, conditions or privileges of employment.
If you feel that you have been discriminated against, you have rights. First, you must contact your regional EEOC, make an appointment, and tell them the situation. After that, contact an attorney capable of handling discrimination cases.
Texas is a "Right To Work" state. What that means in practical terms is that you can be fired for any reason...or no reason at all. You have the right to take your skills, talent, time, etc. anywhere you wish, on the other hand.
If you work for a lousy boss, the best revenge is to find a better position. On the facts you provided, a lawsuit is very unlikely to prevail.