I'm sorry to hear you're so uncomfortable! Sounds like you have a lot going on with your health right now. Heart palpitations can be very scary and certainly annoying, especially when they wake you up at night. They can be caused by a gazillion different things and sometimes they seem to be random.
Have you had an EKG when you're actually experiencing the palpitations? If you have, and the EKG was normal, that's a good sign. Remember that EKGs are NOT for the lay person to read and interpret - all EKGs lines look jaggedy and bizarre and foreign to someone who has not studied cardiology!
Sounds like you've had an echocardiogram, whereupon your doctors found the MVP and regurgitation. Neither of these conditions necessarily would cause heart palpitations, and people with palpitations often have entirely normal echo studies. So you can't necessarily relate the two. When was the last time you had an echocardiogram? Regurgitation CAN worsen, but often it's pretty benign and a cardiologist might just want you to get a repeat echo in 5-10 years or something like that. I have aortic valve regurgitation and a systolic murmur that was found when I was 18 but no doctor has ever been concerned in the least; they simply told me to get a follow-up echo every several years to make sure it hasn't worsened. I just had my second echo a few months ago (I just turned 28 today) and it's still the same, no worse!
Palpitations can be caused by caffeine, alcohol, smoking, thyroid problems, you name it. Millions of people walk around experiencing thousands of palpitations every day and much of the time doctors don't have a perfect explanation for it. These people may be perfectly healthy, eat right, exercise 5 days a week, don't smoke, etc. but they still have these annoying palps. There ARE medications out there that may help - they're called beta blockers - and these are safe for most people but can lower your blood pressure and heart rate, so they're not for everyone.
Have you seen a cardiologist lately? It might be worth asking your doctor about beta-blockers or even another echo if you haven't had one in a while.