A decent labor atty will cost you $235-300/hr. A great one may cost 400 to 500 /hr if you are doing serious battle.
Your initial consult, talking points, tips for what you need to do, and a letter to HR will probably cost you 3-4 hrs of lawyer time. Your CAREER, LIVELIHOOD, FAMILY, PENSION are on the line . . . a few thousand bucks is chump change. Spend it . . . . the cost is minor.
You want to DEFEND yourself . . . if you plan to litigate for damages, you will need really good documentation, a long time frame about about $75K to put on the table. ..... my atty said -- yes you can likely win; it will cost your 75-100 k to win 100-150 k a few years from now . . . . and you may not like the impact on your career options.
GOOD LUCK