There is no DD Marriott. You may be referring to the Courtyard by Marriott in DD. The closest Marriott is the Marriott Orlando World Center hotel.
Also, be aware that the gas stations on 535 charge ridiculous prices. Usually 30 cents or more per gallon more than other nearby stations. The station on Disney property across from Pleasure Island has lower prices. And a mile or so in any direction will lead to reasonable prices.