The scenario laid down by you doesn't put you at significant risk of acquiring N Fowleri infection.
Health Tips
Is it the first time that you have found yourself concerned about acquiring infection or do you find yourself living under the constant fear of getting infected? In case of the former, nothing further to be done but in case it is latter and the start of this has been following an experience of loss of a dear one, you might need to introspect into your anxiety.