Dent on shaft of the penis & bump on side of penis got me wo

Hi, Ive had a few problems that have been ongoing for the past few months and
driving me insane. After a prolonged period of masturbation a lot of strange
things have been happening.
Firstly I noticed a bump on the right hand side of my penis, it can be just
about felt when flaccid and easily felt when erect. This freaked me out big time
at the start but not as much now because of other problems. It seems to have got
a bit smaller but is still there and feels like it could be connected to the
base of the penis on that side because of a dull pain at times. It has been
there for 9 weeks.
About 6 weeks ago i noticed when im erect there is "ridge" under the head of my
penis that is parallel to the corona. It can move about and is especially
prominent just after ejaculating. It feels like something has swollen up, a vein
or something?? just under and around the head of the penis. When im soft and
fully pull back the foreskin i can see a slightly raised area under the head of
the penis but it is only when im erect that this pops out quite a bit. What
could this be?
Thirdly and the most worrying is when im erect and foreskin is fully retracted
down the shaft my penis seems to "dent in" on the underside just where my
foreskin ends on the shaft. It seems to cut in just after where the foreskin
ends and cuts the urethra off at this point making my urethra stick out a lot
more from the "dent" to the base of my penis. I have searched everywhere for
answers and can find nothing, I really feel hopeless and dont know what is
causing this. When fully erect my penis is "cutting in" on the underside where
the end of the foreskin tissue meets the shaft. I was thinking it might be too
tight or something? Although it seems a bit tighter there is no problem
retracting it all and can retract near the full length of my flaccid penis. What
could this "dent/cutting in be"?? I have searched for answers everywhere and can
find nothing. Im thinking about every minute of the day and driving me nuts. Ive
been to my local GUM clinic on two occasions and have no STD's. I tried to
explain my problem but they didnt seem interested once my tests were negative.
They had a look at my penis and said everything was fine when i know it is
certainly not. I have booked an appointment with my GP which is in 2 weeks
hoping for a bit more understanding.
Im sure what the problems are,
1.) The bump on the side
2.) The ridge under head of penis when erect
3.) The dent on the shaft where the foreskin ends on my
erect penis.

This has been on my mind since they appeared 9 weeks ago, the dent 6 weeks ago
and is seriously worrying me. Any help would be greatly appreciated. Thanks