Yay!! Congratulations!!
Definitely celebrate! I think it helps you get more excited about your next goal. I do celebrate with food, but a lot of people on here can't handle the backslide from it...and that makes total sense.
I also celebrate by buying a new pair of jeans (usually from a thrift store/goodwill/salvation army). Definitely buy them cheap because you won't be this weight for long! Congrats again, you are doing awesome!