To weld or not to weld

Hi!

My pool liner is about 5 years old. Last year, I dropped the weight for the stairs right where the wall meets the floor of the pool. It created a tear which I repaired with the usual pool glue and a rounded patch of new liner. That patch held all last summer, through the winter and contines to hold one full year later.

However, I noticed that the indentation around the patch was getting wider and wider over time as the sand/earth beneath it began to shift. A  couple of days ago, I hooked the indentation with the pool brush and created a new tear near the first patch (which is still holding well). So, I applied another patch exactly as I had the first time only this one did not hold. After about 5 hours, there had been more sand/earth displacement and the tear widened rendering the new patch ineffective. In the dead of night, we added another patch (this time bigger) and shored up the outside wall of the pool with earth. The leak has slowed for now, but my pool has drained down quite a bit. The indentation has spread but is now contained.

Question: Should I have the tear soldered/welded and the sand/earth under that part of the pool repacked and leveled? Or, is it time for a new liner?

Thanks!