After doing some research, I cannot find the answer to this question: what's the longest acceptable time frame for a lymph node to return to normal after infection before you should start wondering if there's something else going on? Is it possible for it never to return to normal?

I had an abscess on my neck about 2 months ago right over the tonsilar lymph node on the left side that was about 2 cm wide and stuck 1.5 cm off my neck. It was extremely painful and given that there were no open wounds, my doctor thought it was lymphadenitis and put me on bactrim to make sure it wasn't mrsa. It drained about a day later, but then I developed an allergic reaction to the bactrim and had to stop the course 2 days early.

About 3 weeks after that, I had pharyngitis. That's been gone for almost 3 weeks now and the lymph node has not returned to normal. As far as I can tell, it's the same one that was infected 2 months ago. I've read that lymphadenitis can cause permanent damage to the node (dead tissue and such) and that sulfonamide reactions also affect the lymph nodes, plus it's only been 3 weeks since the pharyngitis, so perhaps i'm crying wolf, but i'm wondering if I should be concerned that this gland has not gone back to normal yet. It's about 2 cm long, firm, sometimes tender, and I can move it with my fingers if I hold my head a certain way. The 2 nodes right above it and below it are also palpable, but not very big.

There are explanations for why the gland should be enlarged, but a pitcher on my favorite baseball team was just diagnosed with cancer, so I have lymphoma on the brain. How much time should I give this before I get it checked again? Is it possible that it'll stay like that and there's nothing wrong?