I have suffered anxiety since before i can remember. My mom noticed it in me when i was as young as age 2. It got so bad that everything in my life started falling apart. I sought out help when i was 16. I started taking lexapro and, like you, it was a complete disaster. after about 10 weeks i got off of that and started taking Pristiq (i only started it probably 3 weeks ago.) i am also in therapy which i started when i started taking lexapro. Now, i had severe SEVERE anxiety...and right now i am proud to say i havent had much anxiety at all in a while. I just want you to know that there is hope. that when you have anxiety you feel like nothing can help and it can get you so down...i have been there before. i never thought i would ever get out of the slum of anxiety but here i am telling you that there is hope because i HAVE gotten out of it..and you can too.
I've never taken Paxil, so I'm not writing this from personal experience of this particular med. Sometimes, especially after long term use, and 11 years certainly qualiries, medications can lose their efficacy, meaning they just don't work for us anymore. This may be the case for you and would be worth discussing with your doctor. His upping your dose to 50mg really isn't that big of a jump. (I AM assuming he's not ADDING 50mg to the 37.5 you're on now!) The maximum dose for Paxil is 80mg qd so you still have some wiggle room left.
If increasing the dose of Paxil is making you nervous, your option is to try different meds. The Lexapro didn't work, but there are many others out there. Some of us have had to try 5 or 6 before we find one we can tolerate and actually works. As I'm sure you know, patience is an absolute must with antidepressants.
I've been on a particular antidepressant for almost a year now and just lately I've begun to feel myself sliding backwards, so at my next therapy session I plan to discuss upping my dose.
Let's hope that someday there is a magic bullet for everything that ails mankind.
I wish you the best
Peace
Greenlydia