Welcome to the lupus forum. I'm sorry that you've not been well. It sounds as if you've had a rough couple of weeks.
Have you looked into the symptoms of lupus? I know the lupus foundation has changed their website, but if you look up on webmd lupus you'll see all the symptoms that lupus patients have. You must 4 of the 11 symptoms to be diagnosed with lupus.
A healthy person can have a positive ANA test from just having a virus. Having a positive ANA doesn't necessarily mean you have lupus. My daughter has had a positive ANA the same level as yours 1:640 from the time she was very young until about two years ago. She has never developed lupus.
Try not to worry or stress out to much over the positive ANA. If you find that you're having symptoms of lupus besides the the tingling/numby feeling, which really isn't a lupus symptom. Then you should ask for a referral to see a Rheumatologist. I would guess that your chest pains may be related to your stress levels, however, I'm not a Dr and if you're still having chest pains you should seek medial attention right away.
I hope this helps you some and if you have any questions, please come back and ask away. There are a lot of knowledgeable folks here.
DX- RA, Lupus, Fibro, LGL Leukemia, Pulmonary Hypertension, Bells Palsy, Gastroparsis, Blood Clots, Glaucoma, Chronic Pericarditis & Pleurisy, Severe Anemia. Way to many medications to list.