Yes, I would say that the lump and loss of erection might be one of the symptoms of the medical problem your husband is having and I second what Bebop said: He needs to see a doctor.

And please let your husband know that he does not need to be afraid or ashamed to talk to his doctor about these kind of issues for that is what his doctor is there for - and as a doctor he has seen and heard it all....... I make sure my husband goes in once a year for a yearly physical & blood work (as do I).