Can you call your insurance and get a list of psychiatrists, then just call around and see who can see you ASAP? I would tell them that you are pregnant and symptomatic.
If you are near St Louis I am sure that the university affiliated hospital would have a high risk pregnancy clinic.
Also- if you call your OB and tell them it's an emergency they should have to get you in sooner. You need to be really insistent and advocate for yourself. Or ask your partner to advocate for you.