What can I to calm myself down?

First of all, I am very sorry for your loss. But Forgetting things is actually a common thing in pregnancy. I forgot stupid simple things all the time, to the point where I had to write down everything I had to do that day and keep it posted on a calendar on the fridge. My doc said, its very common. Dont worry about that too much. But with keeping yourself from getting so upset, you may ask if there is an anti anxiety drug that would be safe to take during pregnancy. Grief is a hard thing to deal with especially if it is going to affect the health of your pregnancy. Greiving is actually healthy. Allow yourself to be able to grieve for your friend so that you can get to the getting over it. If you feel that you are getting too upset, try to get up and do something completely different to get your mind focused on something else.