SO sick, then suddenly not at 10 weeks?

I feel like this is something that gets asked over and over again, so I'm sorry for that but I'm just so paranoid right now! I have been so extremely sick from morning sickness the last 4 weeks. I mean like throwing up every day and barely managing to function. Then all of the sudden yesterday at almost 10 weeks I woke up for the first time without nausea and only had it periodically throughout the day. But then I experienced something new, I was extremely dizzy and lightheaded and just felt generally crappy, like I was going to pass out. Same thing is happening today. No nausea this morning and the dizziness is starting again. Has this happened to anyone else? I know it's normal for morning sickness to come and go, but is it normal for it to be so bad and so consistent for weeks, then suddenly go away one day? And what about the dizziness, is that normal? Thanks in advance!

UPDATE: So I received devastating news today at the doctor. The baby's heartbeat is gone and it stopped growing just a day before these symptoms occurred. I should've trusted my gut that something was wrong, but I convinced myself everything was fine. Since it's a missed miscarriage I have to decide between a D&C; or taking the pill, which only makes this harder, feeling like I have to forcefully miscarry the baby. I wouldn't wish this upon my worst enemy! Good luck to everyone.