Feeling Cold Feet Due to Wedding Stress

I'm in the middle of a lot of stress, and I'm afraid it's feeding into my cold feet towards getting married in January. I started a new job 3 weeks ago at a new hospital as a social worker. I havent been sleeping well due to stress and a small peak into mania. My meds were increased, but now I'm exhausted all the time. I feel like the increase in stress, decrease in sleep, and my impulsive feelings have been causing me to have some second thoughts about getting married. I am not really sure what to do about it, how to figure it out, what questions to ask, etc. I guess I'm looking to see if anyone else has been in a similar situation, and how they handled it.