The knee propblem is most likely swelling secondary to spraining/straining the tendons/ligaments of the joint capsule. These are just micro-tears, and should heal if you let them. Tendons and ligaments do not strengthen as quickly as muscles (especially on juice), and can be damaged by lifting beyond their capacity, even if it didn't feel like you hurt the muscle. A general rule of thumb, ice the injury for the 1st 24-48 hours, and then apply heat. The ice slows down the circulation, and therefore slows down the swelling process. After about 2 days, most of the swelling that will take place already has, so use heat to increase the circulation, and speed up the removal of the excess interstitial fluid. Again, it should heal if you let it - don't stress it until it quits hurting, or the tears will expand. If the swelling doesn't go away, you may need to get the knee drained, and that hurts, so try to let it heal. Also take ibuprofen (motrin, advil), 600-800mg (3-4 pills) every 6 hours with food. Even if it doesn't hurt but is swollen, the ibu has great anti-inflammatory properties, and will speed up your recovery.
As for your chest pain, it was definitely not heart-related. Angina (pain felt when the heart is deprived of oxygen/blood flow or other damage) does not get worse or better with respirations, or with pushing/stretching the chest. It can sometimes get worse with exertion, so if it hurts a little while sitting down, but more when you do anything streuous, it may be cardiac. I know you said it was better today, just thought I'd throw that out there to you.