I can relate to your problems so much... I'm trying to conceive this year and my worries about lymphoma or other cancer are driving me nuts. Every time I think I might be pregnant, I wonder if I'll finally find I have cancer and I'll have to have an abortion and it just tears me up.
I've been having night sweats since November, immediately after getting convinced of having lymphoma and reading a list of symptoms, among which was night sweats of course. My night sweats are exactly like yours, not drenching, just my legs, my chest, my neck, around my underwear... and mild. Moist and annoying as hell.
I also had a chest pain in the right side of my ribcage that I was sure it was lymphoma, but I couldn't have an X-ray because at the time there were chances that I was pregnant. I finally gave up having the X-ray and the pain disappeared.
In January I started having hot flashes and weird sensations on my feet and hands, like cold/hot/sweaty. The hot flashes were more intense around the time of my period and they got me worried that I was entering early menopause (I'm 28). It's unlikely though - a hormonal imbalance is more likely, after all the horrible stress I've been through.
The hot flashes are so disturbing though, even worse than the night sweats. Every time I get angry or emotional I feel strangely hot and feel like sweating. And the closer I am to my period, the worse they are. I do hope they will eventually go away and that they are caused by anxiety (which can be true).
I've started taking Vitamin D supplements when my doctor suggested these symptoms might indicate a deficiency. Ever since I've started the Vitamin D, my night sweats CONSIDERABLY subsided. I even got nasty hot flashes last night because it was hot in the room and I was agitated and God knows why else (hope not cancer!) - and still didn't sweat as much as before. I barely got a bit moist on my chest.
I'm pretty sure at this point that my night sweats are not related to any cancer of lymphoma. I don't yet know what is up with the hot flashes (horrible they are!), but the night sweats are either a vitamin deficiency or pure anxiety. Anxiety can do this to you.
Please try taking some vitamin D supplements and maybe you'll stop having the sweats! It's not worth it to consume yourself and not have a proper rest at night.
I really, really don't think you have any lymphoma! The ultrasounds, the X-ray would have picked it. Besides, you don't have symptoms! You can let that one go, whatever the cause of your night sweats, it's not lymphoma.