I like 'quickly' better than 'hastily' for every day use. Hastily works ok written but can sound stilted in conversation. I would use "I dressed quickly/hastily and arrived at the restaurant by 5." in writing. "I GOT dressed quickly" will raise no eyebrows in conversation, unless everyone in the room is more concerned about exhibiting their superior grammar than actually talking to people. In conversation "I got dressed quickly and got to the restaurant by 5" or "...and was at the restaurant by 5" also sound natural. As with anything, consider your target audience. Teachers or pedantic individuals may not be impressed that your command of English lets you speak like a normal person. "I GOT dressed hastily" sounds unusual. 'Hastily' is less common than 'quickly', which means used in conversation by people with a larger-than-average vocabulary - people unlikely to be throwing unnecessary "gots" around.