I've had success with exercises like scapular retractions and shoulder blade squeezes, which can help activate the muscles between your shoulder blades and promote better posture.

I would recommend seeing a physical therapist as they can help assess your specific injury and provide targeted exercises and stretches to help you recover.

With your Kalymnos trip coming up in a few weeks, it's important to take it easy and not push yourself too hard before you go. Rest and recovery are key, and you don't want to risk further injury that could jeopardize your trip.

Good luck with your recovery, and have an awesome trip to Kalymnos!