Realize that the WebMD forums are not monitored by anyone. Anything that requires an immediate response doesn't belong here. That said, I'm sorry your post wasn't noticed for a week. I have been traveling and not checking in as I usually do a couple times a week.
First, no, there is no relationship between cancer and any of the symptoms you are describing. Prostate cancer doesn't occur in 26 year olds, and it also doesn't change the shape of your penis or urine flow.
GERD is unrelated to any STD.
There are about 120 varieties of HPV, and only some of them are dangerous. There are suppression treatments that are may make it so you never see an outbreak after you are initially treated by a urologist to have any warts removed. You may check out ProCerv HP which although originally targeted for women with abnormal PAP smears, can also be a follow-up treatment for men who have had warts removed.
HPV does NOT mean you can't have sex. But you do need to communicate with your sexual partners, and you may choose to use a female condom which covers more area than a male condom. You can read about transmission and prevention in a lot of places.
The shape of your penis has nothing to do with any of the other concerns you have. And in fact, it probably is inconsequential unless it is causing you some physical discomfort. You may not like the way that your penis looks, but unless you're concerned about parading it out for photos, the issue is likely only one of anxiety and not an issue that should concern you much if at all.
The skin lumps you discovered are likely to also be unrelated to the other symptoms you have reported, and could easily just be clogged sebaceous glands, ingrown hairs, or small water-filled cysts. Obviously these are just guesses because I'm not the doctor who examined you, but they're not terribly concerning.
Now, I do understand that this SERIES of events has conflated into a very negative experience surrounding your genitalia. And while it's understandable that you have dragged your enthusiasm for sex into the dirt, if taken separately as a series of unfortunate events, any one of these could be addressed and resolved.
Unfortunately I cannot address your concerns about GERD. It is not a subject with which I have any familiarity. It is a completely separate issue from any urologic concern.