Hi theunluckyone - welcome to the forum! Like razzle suggested, the "New to Lyme" thread has a lot of great information, and the more you can detox, the better!
Since you're seeing a LLMD, he/she should understand that testing is not necessary for diagnosis - the western blot only tests for antibodies, and the Lyme itself can prevent the body from producing antibodies!
It's so frustrating how often the phrase, "You can't have Lyme - it's just anxiety" is used - I'm so sorry you've had to deal with that! Unfortunately, a lot of us have been there - but the up side to that is that we can relate, and you've definitely come to a good place for support and information!
As far as the diet, most people do well staying away from sugars - it feeds the bacteria! A diet rich in fresh food is key - cutting out the processed foods (which can be quite a challenge!) is really helpful, as this sort of puts an extra strain on your body. The way I see it, the more of your body's resources that can go to regaining your health, the better!
A good multivitamin is always a good starting point - picking and choosing between vitamins and minerals can be tough - obviously they're all good for us! This might be a good thing to bring up with your doctor when you see him/her next, to see what you might be deficient in, what might help your specific symptoms, etc.