Hi Custardtart,
The high blood pressure could be making you more tired, and if you have kids to look after as well, Im sure this makes everything harder.
I have no wonderfull advise for you, I am at the same stage as you in my pregnancy, and am noticing I sleep longer, and have no extra energy from my extra sleep.
I hope you are feeling better emotionally today, I know what you mean about the feeling heavy and it getting you down, keep your chin up.
Sometimes its hard to keep your spirits up when you feel like crap, sending heaps of hugs
Take care,
Mickey.