Welcome to HCM
We understand your concerns
I went through your description. I suggest you not to worry much. As you have doubted, the purple patch you are mentioning could most probably be a vein which could be in the process of becoming more visible. Means, the penis capacity is increasing. Other causes for this could have created more symptoms like itching or burning sensations. Therefore, you need not to worry about this.
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.