Welcome to HCM
We understand your concerns
I went through your description. I suggest you not to worry too much. Please, you must understand that researching through internet and other medias are futile attempt because most of the information follows with a disclaimer. They are somebody's opinions. May not be correct and serves as confusers.
If you are in doubt, do consult your family physician. It is better than worrying continuously without any previous knowledge or experience.
In my opinion the lump is nothing to worry. It could be semen plus dust plus urine plus some dirt etc. This happens with everyone. You are worried because you are under some medical condition.
You might need psychological counseling
., I am more than happy to provide telephone psychological counseling through healthcaremagic. Contact me through customer care, www.healthcaremagic.com.
Hope this answers your query. Available for further clarifications.