I'm so sorry Tessa!
The best advice right now is the following, in this order:
-Get a good lawyer (even if you reconcile it'll still be well worth it)
-Cry, lean on friends/family, do what you need to do to get through the day. Don't be ashamed to ask your doctor for xanax, anti-depressants, etc.
-Lots of websites out there (be careful) about saving your marriage have some great advice - most say to not beg him to come back, etc.
- I don't know if there is another woman involved. Many times there is, so you need to protect yourself in lots of ways - financially, go see your gyn for a check up, etc.
Feel free to PM me if you have specifics!
It's too bad that all the people who are smart enough to run the country are busy teaching school.