I still can get dizziness now if I am not drinking enough fluid. Remember you are in the honeymoon period (first 3 months) so make sure you are drinking enough fluids and enough sustenance daily or you will feel crappy. Even some hydrolight icy poles are a good way to get fluids in or if you know you haven't drank/eaten enough, grab a powerade or similar and focus on drinking that as quickly as possible - but not too quickly or you will end up throwing up lol!!
During the honeymoon period it's great - you can pretty much eat anything and just keep on loosing weight - it's a total rush and high. Then you know it's over when you hit a plateau and they can last up to month or so until you take the necessary steps to adjust your lifestyle. Working with your surgeon and dietitian will help there. I still have to remind myself to eat at times but I always make sure I am carrying a bottle of fluid with me at all times. I can't stand plain water, so I always add cordial, but even adding some sliced up fruit can help peak your interest to ensure you are constantly drinking. I was told once (not sure if it's true) but by the time you feel thirsty, you are already dehydrated. So constantly having a bottle and taking sips all the time will not only help with dizziness but also constipation and feeling better.
Exercise can help (not I've ever done any lol) but making sure your diet is down pat is the most important thing. It will take a few weeks to work out what you can and can't eat (sometimes what you used to tolerate, you can't anymore).
Also make sure you keep an eye out for reflux. Feeling off after eating, but hungry, throwing up often, general uncomfortable etc. I used to have to take a tablet every day. Now I take every 2nd or 3rd day which is good because those tablets can be expensive!
Great news about the initial 11kgs though - it's a great and be happy looking forward to many more kgs lost forever :-)