Hi Kelly its difficult to know exactly what going on in your case without a full assessment. I think that all movement as long as it is not causing you further pain would be good so keep your shoulders moving as well as continuing your stretches. In addition to this you could try some heat on your shoulders (as long as there is no problems with your sensation try a hot bath or hot water bottle). Some hydrotherapy may be use full, you may not get this via your physio in the NHS but you can always ask, if not have a look online in your area some local baths may run some warm water sessions, it may be good to practice gentle movements in warm water. Gentle massage may help to as long as it is not causing you any pain. Hope this resolves soon for you.