Re: Breast feeding, exhaustion and anxiety.
Mine hovered around 90/60 (not terrible, but also not great) for years until the very end of my pregnancy when it finally went up a little bit (it got all the way up to 110/70 during the last couple weeks which is a really big deal for me). I would get occasional dizzy spells, but usually only when I would stand up from sitting or lying down. Last I checked, my BP was 100/60 - so pretty normal (low normal, but normal) - but that was almost a year ago and it's hard to say where I'm at now. I feel good, so I'm not too worried.
I found that snacking a lot throughout the day helped when my blood pressure was at it's lowest. Worry less about big meals and just nosh all. day. long. Nuts, cheese, fruits, and veggies are good to graze on. Tomato juice, like I mentioned, is great for low BP because it is high sodium and has lots of other vitamins and minerals. I get insane cravings for tomato juice sometimes, and I wonder if it reflects BP dips. It's hard to say, but it seems possible. :shrug
Also, light exercise can help. I walk a lot, and I feel much better because of it. A little non-strenuous exercise can help get your blood circulating better. Obviously, you don't want to do anything to rigorous, but a short walk every day can help. Have a snack first, and take juice, Gatorade, or water and a little snack along in case you need it. Sunshine, fresh air, and exercise are good for your state of mind too. ;) As long as you don't overdo it (and that's important with low BP), a little exercise is all around good for you.
Good luck with everything! Keep us posted on how things are going; I'm really pulling for you to start feeling better. :gvibes