I think pursuing your dreams is very important. Taking formal mountaineering courses will help you stay alive throught the apprectice part of your training.
I think you should keep your goals alive, but realistically...
55 is too old to seriously consider starting from scratch and ending up as a Himalay climber. You are 20 years past your prime from a mountaineering perspective. Others may tell you that your age is not an obstacle, but many 55+ year-old climbers already have 30+ years of mountaineering experience under their belts.
Unless you move from Texas to a place where there are serious alpine mountains in your backyard, you're not going to get good enough, fast enough, to serious consider the Himalayas before your age seriously restricts you. Seriously, if you stay in Texas it will at least 10 years before you get enough savvy under your belt to survive a trip to the Himalayas.
I'm not trying to splash water on your fire, just helping you to be realistic. I think a truly achievable goal would be general alpine climbing with ascents of peaks such as Rainier, Grand Tetons, etc. These are still worthy goals.
Frankly, I'm 52 and I've been climbing for almost 40 years and, after 2 expeditions, have NO desire for anything except peaks like Rainier and the Grand Teton. I am living proof that you can spend a lifetime climbing in the smaller mountain ranges and still have the time of your life.