I had a lump form approx that area, palpations of heart, anxiety attacks etc. It was a thyroid nodule that was mostly fluid but it made my thyroid overactive. Might want to have a complete thyroid panel run ...your family doc can give you a referral to an endocrinologist if they don't handle it themselves, some general practitioners don't do it
Are you feeling scared or anxious about it? The breathing problem could be pain from where the injury is, but if your heart is actually beating faster as opposed to just feeling like it, that might be anxiety.