Actually there does not seem anything wrong with the basil plant apart from old age. Time to replace it with a younger seedling and allow that to continue to provide leaves.
Longer version: there are at least 3 different plants known as "albahaca" in Spanish and Portuguese and Caribbean areas; this one we can see from the crumply leaves and light grey mature bark is Ocimum basilicum. This is an annual plant, grows from seed, produces leaves then flowers and seed and dies. It can be kept in leaf production for some time but eventually it just runs out of steam with the effort of pushing nutrients from the roots to the growing tips through the woody stems which just get longer and longer.
It looks as though your pot was started with some soil and a few seeds that grew up in a cluster providing many months of good fresh leaves. The pot is a good size and able to well support multiple basil plants; they have become a bit leggy since they only get the late sun. It's time to do the same again. You can keep it in a vegetative state producing lots of leaves by regular weak fertilization which will delay the flowering and seed production, and more sun would encourage it to be more upright and compact. So your watering seems to be good, just start again and relocate for more sun if possible.