Lump behind ear, under chin, armpit ache

Hi,
A few weeks ago I noticed that I had a small hard lump under my chin, in the soft area in the middle of the underside of my jaw. It is a lump I had noticed on previous occasions, in previous years, but which is not always noticeable. I now believe that it may be a lymph node (at present it is unnoticeable, having shrank).

Around a week later I noticed a small hard lump behind my ear - just under a centimetre in diameter and literally in the crease between my ear lobe and my neck. I don't know if that lump was there when the jaw lump was, because I didn't check. However, both lumps worried me (i was thinking cancer), to the point that I fiddled with them and eventually they became really sore and painful to touch...I then, around a week later, got an aching sensation in my left armpit, running down the side of my breast. I also had the sensation in my right armpit, but not so much.
Occasionally I would feel a "pang" in either armpit, this went on for about 3 days. Despite my best efforts to find one (having read up on lymph nodes) I could feel no lumps whatsoever in my armpits.
Now, a week later, the armpit pain is gone, and both the lumps behind my ear and under my jaw are virtually indecipherable...

What I was wondering is a) what thismay be symptomatic of,
and b) is it possible that the armpit ache might have been caused by my excessive fiddling with the lumps, which I believe to be lymph nodes, behind my ear/under my jaw? as in some kind of reaction in my lymphatic system to the interference?
c) when armpit nodes are swollen, is it always possible to feel a lump, or could it just manifest as an ache? I want to know whether all of this is lymph node related or if the armpit thing is totally separate, as I understand that generalised lymph node pain/swelling is a cause for concern

thanks for your help