Hi Banja,
the first thing you should do is get a complete physical(with bloodwork,specifically thyroid) from your doc. How is your sleeping, do you snore? This can make you very tired during the day. If your health is okay, then I recommend regular exercise. At first it will feel exhausting but after 2 months or so you will feel stronger and notice a change. Try to get out and enjoy a little sun - this helps. Keep taking the vitamins and make sure you take them with food. Also B vitamins are good for energy. Stay away from pop and processed foods because they will suck your energy. I guarantee that exercise if done regularly will boost your energy. Weight lifting in particular makes a person feel stronger very fast. I hope you feel better soon.