Your Salah is valid, In sha’a-Allah (if Allah wills). The Prophet (peace be upon him) is authentically reported to have said,
“Pray standing, and if you cannot, then sitting.”
Standing is one of the pillars of Salah for those able to do so without help or with the help of something like a stick.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.