A lot of good advice here. I think it's wise to be cautious no matter how much time has passed since your wife died.
The age gap may not mean much to you at the moment at the start of what could be a new relationship, but in time it may well become an issue as you get older. I have seen it with a family member whose partner is 20 years younger than her. She is 61 and four years into the relationship the difference is beginning to show.
For example, she wants his company all day as she is retired, but he needs to work and she is left on her own much of the time - something she didn't 'sign up for' (her words). It doesn't help that she has no hobbies or interests or has tried to find something to do with her time.
Companionship at this stage is perhaps as far as you should go. Take your time, think about your future and how you would like/not like it to be. We can all make mistakes, but make sure this is a good risk before committing yourself to anything more.
Times article claim that Waspi women are tone deaf and should read the room
Good Morning Sunday 17th May 2026
Unite the Kingdom and Pro Palestine marches Cup 16th May 2026
and to his friends' despair lavished money on an unmarried woman and set her up in a lovely new house. He found out a year later she was seeing other men, and she refused to leave the house he'd provided for her. 
