Hi GSR
I have just joined the site too as, like you, these things wear us down with worry. I haven't been in the exact same position but I know that I expressed concerns to my surgeon several times about lumps in the non-cancerous breast and armpit and he was clear that my tests on these were recent and therefore there was nothing to be concerned about. Your lymph node biopsy was recent and your op was really quick too so I would try and stay positive. Surgery/treatment causes lots of oddities and they are usually fine.
Be as normal as you can be with your lovely kids!! It's hard, I know, but my kids are what keeps me going!
Stay strong and positive!
Good luck with what the hospital say. x