feeling confused and depressed

Anne
I'm now 7 weeks pregnant with my 4th child. This pregnancy is so very different to my last 3. I have had high blood pressure, dizziness and finding it hard to function. I'm crying all the time and just can't find it in me to be excited. I find doubting myself all the time. Is this normal to feel this way? 
I don't want to sound selfish I know there are a lot of people who can't have kids or who have been trying for a long time to fall pregnant. I'm 35 years old and my youngest child just turned 11. To be honest with you I'm scared! 
I have no energy and can't bring myself to goto work. I just don't feel like me. 
Is this normal???