Question

Yesterday, immediately after the Amidah of the evening prayer, I realized that I had prayed very quickly—the whole Amidah took me under 30 seconds. It’s impossible for me to pray that fast, and it’s clear that I didn’t say all of it. So the question now is: am I obligated to pray it again, or perhaps since it isn’t clear to me which blessing I left out, with regard to each blessing individually I should say that in cases of doubt about blessings we rule leniently?