Whoa Debra!
Take a deep breath (or 2 or 3 or however many it takes to relax).
Just about everyone on this forum (1500? members) is a SURVIVOR of Valve Replacement Surgery or a family member of a Survivor.
Yes, Valve Replacement is major surgery, BUT it has evolved to a Very Successful Artform, especially with highly experienced Valve Surgeons. (1% risk of mortality, 1% risk of morbidity for first time Valve Surgery under age 60 or so vs almost certain demise in a few years if left untreated)
It would be wise for you to obtain a copy of your Echocardiogram report to become familiar with your parameters and how they compare with the Normal Range. Copies can be obtained from the facility which performed your procedure. You may have to pay a copying charge. For Aortic Stenosis, one of the Key indicators is the Effective Valve Area. Anything less than 0.8 sq cm is considered a trigger for recommending Aortic Valve Replacement.
It would also be wise to get a second opinion, preferably from a SURGEON and preferably from a surgeon who performs a good number of Aortic Valve Replacements (say over 100 per year...the Really Prolific ones do up to 400 per year). Once a Cardiologist has diagnosed your Valve Disease, there isn't a lot they can do other than possibly medicate you to slow the progresssion of your disease and to refer you to a Good Surgeon.
To learn more about the experience, I recommend starting by reading the "stickys" at the top of the Thread Listings for the Pre-Surgery Forum, Post-Surgery Forum, Valve Selection Forum, and Anti-Coagulation Forum. THAT should make you tired enough to get to sleep -)
Feel free to ask more questions as they come to your mind.
Remember, If we can do it, SO CAN YOU !
The Really GOOD NEWS is that your condition was discovered in time to get it FIXED to prolong your life.
'AL Capshaw'