I only have an android handset active on vm right now, and to be honest I think they route them more like sprint phones... the speeds are down for sure right now (well download is , upload as always is speedy since hardly anyone is using the upload)... but it sounds to me like either the tower is flaked out or your device is acting up.
Do a re-program of your device (where you enter your mdn and msid).
If after the re-programming it still does it disconnect it from power for 40 mins (to try to clear any invalid tower records for your device).
If it still acts up, take it to a location nearer the tower, If it works nearer to the tower then it's most likely you are at the edge of coverage and it could be shrinking during peak usage (darn old school cdma physics)... or sprint could have killed a tower lease since your last plan was used (I've seen this happen a few times, I have also seen them re-add, and add new ones, it's a numbers game it seems).
If getting closer to the tower doesn't fix it take it with you the next time you are going more than 10 miles from your current location... if it works fine in the other location you know it's your tower... if so report it to VM and hope that sprint ever gets the report
If you find it is your tower a faster way to get towers fixed is to verify it with your friends or other people's contract sprint phones, and have them report it as well.