What shall I do ?

Your one in a million, you put others before yourself. I'd say your hubby is right about them already being in contact with the virus.Come on you both need this time away, you do a great job & it can't always be easy with two special kids to care for.Go for it im sure your sis would want you both to go, And end of the day you"NEED" this short break. Have a great time , Enjoy.