Im sorry i meant extreme chest pain*
Hello and welcome to the Pain Management Forum. I apologize for my tardy response. And I am very sorry to hear about your pain and the unacceptable treatment you have received by physicians.
There are a multitude of things that could be causing your pain. They may not be related to your appendectomy or have no relationship to the procedure. I would only be guessing at the possibilities that explain the lump near your sternum, which could include a cyst or an infection. Painful inspirations could be multiple causes also from inflammation or other similar conditions.
What I do know is it is very important that you seek medical attention asap. You should have a chest x-ray, CT and some lab work at the minimum. If you have not been taken seriously by the physician you have consulted than do not return to them. We sometimes forget that they are not God's. We hire a physician to perform a service, they work for us. They are not doing us a favor, we are paying them for their services. If your PCP does not listen to you and treat you with respect it is time to fire him and move on. Would you allow your plumber not to complete a job or pooh-who concerns of pipes that are leaking? Of course you wouldn't. Than don't allow a physician to do with your health either.
I don't think this will go away on it's own. I absolutely think that you need to be evaluated by a competent medical provider. Indeed if your pain is severe and you have pain with inspiration you may want to consider a trip to ER. This is not a normal condition. I wish you the very best and will look forward to your updates. Please keep in touch and take care, Tuck