Maybe see if u can get ur B12 and iron levels checked. Good luck I had 3 weeks of dizziness and it was horrible I couldn't do very much at all.
If you're having trouble breathing you should seek immediate medical attention because if you're not getting enough oxygen neither is baby. That's what my doctor told me. As for the dizziness and blurred vision I get that too. It's my body's way of telling me I need more fluids. Usually a Gatorade and about 15 minutes of laying down helps. Make sure you don't stand up too fast that can make you dizzy too. I'm 13 weeks and made that mistake this morning.
those are all symptom of pregnancy sweetheart :) perfectly normal, your internal organs are moving up towards your stomach now and that tends to lead to heartburn and A LOT of women say trouble breathing as well.The other symptoms really are based off of your hormones, and the changes your body is making for your sweet little one. However you can always talk to your doctor to ease your concerns. hope this helped and good luck with the rest of your pregnancy :)