Easy fix: when tempted to use the adverb maybe substitute its meaning perhaps and see if the sentence still makes sense.
Maybe the reason you have so much lobster peel is because you didn’t use SPF+30.
Perhaps the reason you have so much lobster peel is because you didn’t use SPF+30.
In both instances, the word maybe and it’s meaning perhaps are interchangeable.
On the other hand, you very well may be using the verb be and its auxiliary may when you are driving without your GPS and realize, “Oops, I may be lost! Oh, Siri!!!!”