If you saw one then at least you have a starting point for next time buddy.
I wouldn't worry about not having caught this year. It's been winter, the hardest time you could possibly be fishing. We've not really had any prolonged periods of high temperature to get that water temp up. Tbh this last 5-10 years I've considered March to be part of winter rather than spring (in fishing terms anyway).
Clocks go back in a week or 2. All this blanking and freezing our nuts off will soon be a thing of the past. No need to panic yet.