Go down that list again, and first prioritize those that are the most disturbing or bothersome? then list when issues started and how often for each?
I'm no doc. I am just a mere person who's gone thru the diagnosis food-processor and maybe can point you to resources to help you sort it all out.
Also are you on any meds? Sometimes a med or two, or even supplements can cause problems for some.
Can I assume that the weight loss in such a short time is a main concern?
When you see your GP, sort these issues into clumps...of priority or that you think are connected. I find that usually GP's have short attention spans-so keep issues to the main ones.
If it were me....I'd come in with a list of three 'big' issues and two minor ones and then after main testings work my way down the lists.
Have you had a bad 'flu' or a cold' in the past few months? That could be a key to some issues...or not, just a thought.
It sounds like some things are sort of piling up and it seems almost to be a car wreck. But both I and others would need some key specifics before anyone gets an 'AH-HA! moment or even an idea of what's happening to you based on our experiences and/or readings.
Hope this helps? - j

Occurs to me you might start reading up on diabetes, hypo/hyper-thyroid, and gluten intolerance/Celiac's...not that you have these, but many of your issues could overlap with these. Here's the link to the Gluten forum...be sure to read the 'stickies' at the top of the forum- they have lots of basic and advanced info.
http://neurotalk.psychcentral.com/forum13.html Just click on the blue letters and you find yourself there!