Andi,
I can not say that it "All" comes gushing out, but I too experienced a period when it seemed as if I could not hold my urine. Like yourself, it ws getting up from a sitting position. I found two things that helped.
#1 - Before I get up, I squeeze to hold in and while getting up, I sort of roll to one side rather than standing straight up.
#2 - Make sure I go on schedule. I'm sure you've learned that voiding is now a timing rather than urgency thing. I found myself waiting too long and was full when I got up to go. Now I do my best to go every two hours.
In any case, consult your doctor. If you don't get the answers you need, try for another opinion. Second opinions are not just for treatment options... this is important too!