I agree with mbar. You should try to contact a fiberglass pool mfg. FG is gaining popularity all over the country, so there must be someone nearby that could advise you.
When I put my pool in, I sunk a 10" wide by 8' rigid pipe along and under the deep end of the pool. That way I can pump some of the groundwater away from the pool if I ever need to drain & service it. Your pool may or may not have such a drain. In any case you will have to remove the pressure from the outside of the pool before you can make a repair inside. Not exactly sure how to do it, but it may involve breaking part of the patio and removing the soil around the area where the problem started.