You can just update the search with the filter starting from the end of your initial search. (you can add a 6months overlap since some publications can be delayed in their apparition in some web search).

I don't think that you need to redo work or start all over because of a one year gap, but I am concerned because it appears that you are doing this on your own. A systematic literature review requires multiple people (see e.g. https://training.cochrane.org/handbook/current/chapter-05#section-5-5-2) therefore it seems that what you are doing may not qualify as a systematic literature review.

Hello Najam Sahar, I'm not a librarian, but I wouldn't think you would want to lose all your previous work, so if you have a search string/ strategy, can't you just use that and apply a date filter.