A healthy source of moderate duration and intensity of natural--or artificial uv rays if your climate dictates--sunlight while closing your eyes and meditating is a great lifter of spirits. Moderate excercise is good for the body and mind as well; I find that dancing is the most fun form of excercise, as it involves music, with swimming being the second most relaxing way to excercise. Also, get plenty of sleep if possible (about 8 hours per night) and avoid junk food. Find a new hobby if possible.
Omega fish oils, I must agree, are completely foul tasting in every way. I do not recommend them at all, but then again I don't even like the taste of fish so I may be biased on that point. B vitamins have been rumored to relieve anxiety, but I have seen absolutely no evidence to support that assertion.
As for mood improvement, I would suggest smoking pot, though I realize that answer may not be what you had in mind by using the word "natural." MJ obviously has the drawback of being illegal and rather expensive and also hard to conceal from those with whom you may reside and who do not approve of your usage.
Kava-kava is a mild mood uplifter/antianxiety agent, as is Valerian root, though Valerian root smells bad (though still not nearly as bad as fish oils). You might try St. John's Wort as well. A multivitamin every day probably wouldn't hurt anything, either.
Be sure to eat healthy foods and think positive thoughts, such as what you are grateful for each day. Remember, life can always get worse, sometimes much worse.
Also, find a friend/confidant to help carry your burdens. Feel free to PM me if you want. Good luck. Hope this helps.