It's inconclusive. You can test again for it later, if you want.
You don't mention any encounters prior to your symptoms starting, or the timeline. If it's been more than 4 months since your most recent encounter, I wouldn't worry. If you are concerned about a more recent encounter, test again at 4 months.
Your symptoms are not indicative of any STD.
It doesn't matter if it was a combo test - at 7 months, it's conclusive. You don't have herpes.
Have you had a digital prostate exam? That's where they use a finger and feel your prostate. It sounds as if you may have some inflammation in the prostate (not caused by herpes), which can cause a lot of the symptoms you have. You could also have a compressed disc or pinched nerve that is causing a lot of this.
There is no STD that causes all over body symptoms like you are describing. No STD would cause tingling in your arms and hands, and no STD would cause little red bumps that disappear in a few hours.
I'm not sure why you are focused on an STD - guilt? anxiety? germ phobia? - but you aren't doing yourself any favors by not letting this go. If you have something else going on, you need to be open to other possibilities so you can get it treated. It's the only way you'll find relief. If anxiety or guilt is the issue, and you can't let it go, then please consider seeing a counselor. (I don't mean to sound critical - I really just want you to start feeling better.)
No, your result is conclusive. The IgM is designed to look for newer infections, and is really unreliable, so you wouldn't need that at all.
Your IgG was taken at 7 months, and the window period is 4 months, so you're all set. :)