I wouldn't trust the test strips. If the TA was truly that high, then the water would tend to rise in pH if you took out any Trichlor tabs (which are acidic), especially if you aerated the water some.
As you've learned, you don't want to add so much acid as to lower the pH much below 7.0, especially in a vinyl liner pool as low pH is the worst thing for a vinyl liner (as well as metal). If your pH is still low, I'd at least raise it to 7.0 for now. To raise the pH with only half as much rise in TA, use 20 Mule Team Borax (instead of pH Up).
How did your Hardness get so high? With test strips, you can only test Total Hardness (TH), not Calcium Hardness (CH) which is what you really want to measure. Have you measured the TA and TH of your tap water? Is it well water? Oh yes, I see that you said that it was indeed well water. Well, that can explain the high hardness and even high TA. However, with high TA you should have seen the pH tend to rise.
I strongly suggest you get yourself a good test kit, either the Taylor K-2006 you can get at a good online price here
or the TF100 from tftestkits.net here
with the latter kit having 36% more volume of reagents so is less expensive per test.
If your TA and CH were truly that high, then getting the pH into normal range would likely lead to calcium carbonate scaling. Have you been using Cal-Hypo from HTH as your source of chlorine? Perhaps that is the problem since it increases CH. The following are chemical facts for chlorine sources independent of concentration and pool size:
For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by 7 ppm.