What Is The Alarming Level Of High BP?

Hello,I am a 37 year old female. I am currently being treated for bipolar2. Ihave been on numerous meds over the course of 3 years and cannot find a winning medication. I had a high risk pregnancy in 04 where I suffered from Pre-E, HELLP Syndrome, PIH, Pancreatitis and pre-term labor. I suffered from PPD severely with my 1st child and again in 06 with my next child. I was hospitalized for it in 07. My BP remained high for 1 yr post partum. I have been med free for my BP for 2 years now. I was recently put on lexapro 10mg and Effexor 75mg. My BP has been very high lately and I believe that it is from the meds. I have been getting readings of 145/90+ since 6/10/10. I have a home monitor and I just got a reading of 183/111. I have had several other readings in this range over the past few days. I am also being seen by a sleep clinic trying to properly diagnose my insomnia. The Dr at the hospital got my reading as 170/90. I saw my PCP last week and my reading was decent and he advised me to call my psychiatrist to discuss my meds and concerns. I have been waiting for a call back since Tuesday!! My friends feel I may need to go to the hospital. I have had headaches off and on as well as dizzy spells and tenderness/numbness in the left arm. I am unsure if my monitor is calibrated correctly, so my husband is borrowing a BP cuff from a friend tonight-we have a stethoscope. He was an EMT for several years, so I trust his ability to read my BP accurately. At what number, would you say I need to go to the hospital at? The numbness and dizziness is decreased right now. Thank you in advance for any and all advice that you can give me!! Sharon