Rav Leff says no, there is more than one person you can marry, and you don’t need to worry that you missed your beshert.
People get confused from a story about the Steipler. An alte bochur came to him and asked him why he’s not married yet, and he said, “you met your zivug but you said no to her.”
The problem is that most people don’t know the second half of the story. He came back the next year, and the Steipler asked him why he’s not married yet. He said, “But you told me that I missed my zivug.” The Steipler said, “So what?”. He got married and had a happy marriage and lived happily ever after. (heard from the son of a Rav who knows the boy).
I read that Rav Chaim, Shlita, says that people heard something his father (the Steipler) said about zivugim and took it out of context and came up with ideas that never existed.
Bottom Line: Don’t worry too much about Medrashim and Kabala when it comes to marriage. Rely on your common sense, marry someone you like who is a good person and makes sense for you, get married l’shem Shamayim with bitachon in Hashem, and whoever you marry is your beshert by definition of the fact that you married them!