When I read your story, there is one thing that I am concerned about. Please please please do not take it the wrong way. Sometimes, the way we read words, the meaning of the words are perceived as how we the reader want to perceive it. So I want to let you know first, that I mean well. I do not know you, and I cannot begin to imagine how down and sad you are feeling, but I hope that I can be the one to point out this 1 thing.
I can see that you will be a a good mother for your child seeing how much you want a baby. There is no greater blessings than to have a mother who love her baby dearly. However, it is not good for your future baby and for yourself if you have anxiety issues often. When you give birth to a baby, the first few months, your hormones will be imbalanced, it causes us to have slight depression. So mommies must have a good family support. Newborn baby will demand so much of our energy that a lot of mothers are pushed beyond their limits. Having a baby is really all ribbons and flowers like you see on TV or advertisement. But what they didn't show you is: tired mothers, tired husbands, no sleeps, no me-time, little or no rest.
So.. I hope you can change your mindset.. I know that saying "do not be too anxious" is easier said than done. But you know that being anxious is not good for your health and it hinders with successful pregnancy. I suggest that you take a break, either doing meditation, or holiday, going to Church, or whatever you find relaxing. Refresh your mind, throw away all that negative thinkings, and fill it up with new positive things

In the meantime, find a hobby that you like (not baby related) and do that hobby. The purpose is to get you lesser anxious about being pregnant.
Go out with your good friends to chat (not about baby stuff) and relax. Have a short holiday with your husband to enjoy the moment. You have no idea how many mommies out there who are desperate for an impromptu gateaway with just their husbands.
The grass is always greener on the other side. Woman with no kids envy woman with kids, and believe me when I say, women with kids ENVY women with no kids.
Always remember to count our blessings.. Enjoy what God has given us. Think about what you have that others don't. I always believe that every child is sent from Heaven for us take care of. And that will happen according to God's timing. I sincerely hope that you will have what your heart desire very soon

Good Luck!