My poor Volvo seems to be going through a rough patch and I was hoping someone may be able to advise.

The problems are threefold:
1) I think my rear main seal is leaking. Near the driver's front wheel under the engine=oil. Isn't that the RMS? I knew it has been dripping a little, and I've been riding it out until a)something terrible happens b)I have $700+ to have it fixed or c)see a.
But here's a HUGE concern: I casually checked the oil a few weeks ago, and it was DRY. I just changed the oil and filter about 1-1/2 months ago, and I knew it had been dripping slightly, but no indication or evidence that much had escaped somehow. Just gone. So I put 5 more qts in immediately, and the level has stayed high. Mystery.

2) The cylinders began misfiring yesterday. I replaced the plugs and rotor about 8 months ago with Bosch Platinum 2's. It's cylinder #2.
What is the order of the cylinders so I can check the plug? I took one out before I ran the codes because I suspected misfiring, and it was clean. Could the cables be the problem?

3) When I removed the plug cover, there was a fair amount of oil in the crevices on the head. Yikes. The filler cap seems snug, and there isn't oil everywhere, just around the head under the cover. What could be causing that? Head gasket seal?

Anyone have any clues? I'm getting the RMS fixed soon, but the rest are leaving me puzzled about even where to begin.
Thanks for any help!

Michael 1996 855 130k