First off, i'm sorry to hear about what you're going through. Fortunately, everyone here can relate to your story, and let you know that there's a light at the end of the tunnel!
All ssri drugs take about 1-2 weeks to take effect. I've done this twice now, and for me, the 25mg starter dose doesn't do much -- it's just there to get your body ready for the full dose. Then, once you start the 50mg dose, you should start feeling less anxious in about 2 weeks. Generally, they don't ramp you up to 100mg right away -- i'd wait to see if 50mg is enough to control the symptoms, and after being on that for 2-4 weeks, then consult your doctor about moving up.
Your doctor will probably give you something to help you get over the hump until the ssris kick in. Benzodiazapenes are the most common, and they're essentially a low-level tranquilizer you can take when the anxiety gets really bad. They made me really sleepy, but I have talked to others who didn't have that side effect, so you can see for yourself what works.
Counseling will help you a lot. Look for cbt (cognitive-behavioral therapy) specialists in your area, either in group or individualized therapy. They can help you learn to handle your symptoms. For me, it was feelings of chest pains that I thought were heart attack symptoms (i was 23 at the time) and lately, a feeling like my throat is closing off and I would suffocate. I know these are just symptoms, and are not life-threatening, so when they come, I can remind myself "this is anxiety."
i also recommend the books "the panic and anxiety workbook" and "been there, done that, do this". Don't know the authors, but you can find them in the self-help section of your favorite bookstore.
All the best! I'll keep you in my thoughts and prayers.
Peace and blessings,
paul
i also highly recommend some type of counseling along with