D..
I looked back at your other questions, and I admit that I have a little concern about you based on what you've asked in the past. You seem to have a bit of trouble coping - remembering to pick up your kids, asking us how to remember things, feeling guilty about stuff as a mother, etc. This question about how to find courage in your pregnancy seems more of the same.
Have you had depression? I wonder if your doldrums might be more than just pregnancy woes. You really do need to talk to your doctor and see if this is a possibility. It's important to deal with this head-on. Post partum depression could rear its ugly head and cause you so much pain after the baby comes. And now you have other children to take care of during the pregnancy and that's important.
I had trouble gaining weight with my second pregnancy. I found that milkshakes helped. You can make some healthy shakes to take the place of food. Find out what indigestion medicine you can take while pregnant. Whatever you do, don't eat bagels before bed. OMG. The yeast in them did me in lying down.
Please go talk to your doctor.