If masturbation is forbidden, then how can a person release the desire that was created within him, and can it be suppressed? And what is the response to what came in "Al-Fatawa" by Sheikh Muhammad Metwally Al-Shaarawy that contradicts this?

Allah has permitted marriage for the release of desire. As for one who is unable, then he should fast, due to the Prophet's (peace and blessings be upon him) saying: "O young men, whoever among you can afford to marry, let him do so, for it is more apt to lower the gaze and guard the private parts. And whoever cannot afford to do so, let him fast, for it will be a shield for him." Had masturbation been permissible, the Prophet (peace and blessings be upon him) would have guided to it. The Muslim must curb his desires through the fear of Allah.