6 Liters of fat is a very significant reduction in fat volume. It will take longer for your body to recover and for the swelling to resolve. Your body is remodeling and collagen is growing based on the Smartlipo Laser heating your skin to stimulate collagen production and skin retraction. It will likely take at least six month for you to see your full results. I advise patients to weigh themselves once a week to ensure they are not gaining weight. It may also help you to visit your doctor and review your before and after photos.
Many of my larger patients are often shocked at the drastic improvement they notice when they compare themselves with their before photos. If you've had lots of lipo, you can expect to have lots of swelling. Swelling improves with compression garments and regular professional massage therapy - the key word is professional. If you haven't done these regularly, get started right away. Also, make sure your diet and eating habits are on track. No amount of lipo will compensate for poor eating habits.
Removal of 6 L of fat/aspirate is significant. However, if you're still bruised you most likely still have a lot of swelling present. Results vary depending on what your starting weight was and it is now. Remember that any liposuction must be accompanied by continued weight loss management too.
In this instance, I would recommend a 2nd opinion. Now, having said that, you will need to most likely give yourself at least another month for healing. I'm not sure I support the statement that stress has affected your healing, but sometimes the mind can interact with your body in strange ways... Ask your friends who they recommend and it never hurts to seek out other opinions.