Thanks for your question.
This verse has been often misread: "...that the scripture might be fulfilled, [he] saith, I thirst." To assert that Jesus said "I thirst" just to fulfill one small prophecy (Psa 22:15) as the only one which he had not yet fulfilled, is a trivialization of Scripture. Here the word "fulfilled" is not the normal word for the fulfillment of prophecy (not, for example, the same as in Joh 19:24,36); its meaning is: "that the scripture might be finished...(ended, or completed)". Jesus was reciting the psalm, but was too parched to go on, and at Psa 22:15 ("My tongue cleaveth to my jaws") he desperately needed a drink, and having received it, he was able to go on to the end ("It is finished"), spoken with head uplifted.
I hope you have found this helpful.