go into recovery (nandroid to be safe and make sure your apps all have a current backup) and wipe dalvik and cache , DO NOT wipe data, you are simply flashing over what you have. you shouldn't loose much at all other than some settings, widgets and customization
flash the stock rom , try mms
if it works than most likely you deleted something you shouldn't have
go back through deleting/freezing stock apps but do a functionality test after each one
Ok so I looked into fresh 3.4 its custom and I am wondering is that safe because you said not to wipe my phone but fresh forum comments says I should wipe it since it is a new ROM? is that a good idea? I backed up my current settings so if this goes wrong will I be able to just flash back to this stock root?