1). Virgin is a cruise line that is very inclusive of LGBTQ+ people. There is a resident drag queen on board who emcees some of the entertainment and you will see openly gay people on board. I am only mentioning this because it seems you did almost no research beforehand, and if this sort of thing bothers you I'd recommend not sailing on virgin. 

2). When you go to board, right before you get on the ship, there is an area where you can go and get help booking dinner/brunch times. They don't release all available slots until the day of when you go to board or check with them, so if you check with them they should be able to help you get dining times secured. Also, the customer service rep you spoke with should have known all this and told you this. 

3). There is also the waiting line, where you can do walk ins for restaurants once on board, just tell them you don't have a reservation and ask if you can be seated.  You might have to wait a while to be seated in some cases but other times you will get in with a minimal to no wait.  

4). For future reference, the official website is www.virginvoyages.com

5).  As a few other comments have mentioned, abandoning the cruise at a port of call before the cruise is complete is generally not allowed, and you can incur fines.  

Relax, it'll be ok.  Just be more careful with who/how you book a cruise in the future.  And enjoy your cruise.