How can one rid oneself of constant thoughts about marriage, especially with those around being preoccupied, while relying on Allah Almighty to marry me off at the time He chooses, and what are the ways to occupy oneself in a manner that reduces anxiety about the future?

The desire for marriage is an instinct, and thinking about it is natural, but one should not waste time on it. To get rid of this thinking, the following is recommended:

Seeking help from Allah: Through supplication and humble entreaty to Him, for He answers the distressed and removes evil. Allah (the Exalted) says: "Is not He [better than all those who you associate with Him] who responds to the distressed one when he calls upon Him and removes evil?" (An-Naml: 62). Remembering Allah and reciting the Qur'an: For in remembrance there is tranquility for the heart. Allah (the Exalted) says: "Those who have believed and whose hearts are assured by the remembrance of Allah. Unquestionably, by the remembrance of Allah hearts are assured." (Ar-Ra'd: 28). Avoiding idleness and occupying one's time: With what benefits in this world and the Hereafter, such as beneficial knowledge, righteous deeds, and the companionship of the righteous. Recalling Allah's will and decree: For what He wills comes to be, and what He does not will does not come to be. This leads to contentment and submission. Allah (the Exalted) says: "No disaster strikes except by permission of Allah. And whoever believes in Allah - He will guide his heart." (At-Taghabun: 11).