I turn 66 in April which would be my full retirement age, and I am taking my deceased spouse's benefits, but when I called Social Security, I was advised that I should take my benefits now, plus I am still working. I thought I had to wait until April to take my full benefits.
You would have to wait until April to receive your full rate. If you switch to your own record 3 months earlier than that, your benefit rate will be permanently reduced by roughly 1.67%.
What you should likely do instead is wait until age 70 to file for benefits on your own record. That way your benefit rate will be 32% higher than it would be if you start it at age 66, and you can continue to draw your widow's benefits in the meantime. You may want to run the maximization software available on this website to see what it recommends.