if you are actually having alot of muscle spasms going on,chances are,that big wad you have there is actually one big trigger point of tissue and muscle(does it hurt when pressed or radiate out pain from it?). have you been overly stressed lately or doing alot of excercise you normally don't do? sometimes this can bring on alot of spasms. the more in depth reasons would be something like the spinal nerves are constantly inflamming(sending signals) to the muscles which in turn casues smaller trigger points and spasming.
are you having any mechanical/structural(inner pain) type pain or feel pain in your c spine area,or mid back,between the shoulder blades or having any other symptoms besides just the spasms(anything runnig down your arm or in the fingers?)? have you seen your doc about this? have you tried advil or even better,aleeve?(it just lasts longer) to see how it might work for you? since the stuff you are feeling generally stems from some level of actual inflammation,an anti inflammatory would probably help some.
i really would at least check in with your doc here on this,that just sounds like alot of spasms to just 'have" for no real reason. it just needs some evaluation. a good PT may be able to help some,but if this is actually stemming from another real source within say,your spinal area? those TPs will keep coming back til the generating source of the TPs is removed from the picture,you know what i mean? just seeing your doc would help some and get the ball rolling towards you feeling better much sooner. he can also help with the spasms by rxing some level of anti spasmotic for you. you just need to find out why these are so bad. more often than not,more people tend to get this stuff right up in that c spine area(this is where my TPs are the worst) more so than where you are having this down further in the thorasic area. just make that appt with your primary. good luck with this,and please keep us posted, FB