PK
Congratulations. It sounds like you know your limitations. You don't need to make a decision to do or not to do the Blue Hole until you have been in Belize for a few days.
As has been said before, dive the reef for a few days and you and your dive master can evaluate your readiness for advanced diving. Some of us are not interested in the Blue Hole. You might decide that a trip to Turneff would suit your needs. It is a little closer and a little less money. As with Lighthouse, it is an all day trip with 3 tank dives. I love going there.
I would recommend Hustlers as they do reef and atoll diving. If you do multiple days diving with them they will give you a discount. Billy Leslie is the dive operations manager and one of the best dive masters on the island.
When are you going?
Harriette