My cat wasn't acting like herself a few months ago so I took her to the vet and...?

she had swollen tonsils. They put her on antiboiotics and had me bring her back for a follow up 2 weeks later. I took her back and they discovered she had swollen lymph nodes in her neck so they did complete blood work and a fecal examination. Both came back normal. They also put her on another round of antibiotics. I took her back for another follow-up and one lymph node was still slightly swollen so they did a fine needle aspiration/biopsy to check for cancer and infection. The results were negative. The vet said to give it 2 months and bring her back again because more antibiotics may be necessary. It has been 2 months and I'm wondering what to do? My cat is her normal, crazy, obnoxious self, and I've already spent almost $1000. Veterinary care in Cali is EXPENSIVE and I have no problem spending money on my cat. I just don't want to spend it if it isn't necessary. Also, I don't want her to keep getting antibiotic injections if it isn't needed. (The antibiotic they had her on was a shot that lasted in the bloodstream for 2 weeks). I guess in my way of thinking, if the bloodwork, fecal examination and biopsy all came back normal, doesn't that mean she's okay? I forgot to mention, they gave her a complete physical examination and checked her all over and nothing seemed off in any way. Any advice would be appreciated. Thanks! Oh, and she always gets her vaccinations and she takes Revolution for fleas and heartworm. She's an indoor only cat and an only pet. Thanks.