Your purpose for creation is to serve Hashem. We weren’t created for our personal gain per se, even though we do have personal gain in this world, but that’s not the main purpose of creation.
As it says In Likutei Amarim Tanya Perek Lamed Gimmel:
וְזֶה כָּל הָאָדָם וְתַכְלִית בְּרִיאָתוֹ, וּבְרִיאַת כָּל הָעוֹלָמוֹת עֶלְיוֹנִים וְתַחְתּוֹנִים – לִהְיוֹת לוֹ דִּירָה זוֹ בַּתַּחְתּוֹנִים, כְּמוֹ שֶׁיִּתְבָּאֵר לְקַמָּן בַּאֲרִיכוּת.
This, in fact, is the whole [purpose] of man and the purpose for which he, and all the worlds, both upper and lower, were created: that Hashem should have such a dwelling place here below, as will be explained further at length—how this earthly abode for Hashem is the purpose of all creation.