Sounds like it could be unbalanced diet and/or overtraining .Vegetarians often have trouble getting enough protien and fat into their diet.Just be sure to always include some of those protien/fat items you mentioned with your pasta and rice or combine foods in such a way to create complete protien(ie beans and rice)and then maybe add add some olive oil or flax to a side salad.Same goes with the simple carb snacks .Try a trail mix or soy nuts with some of those fruits and muffins.If this doesn't solve the problem(I know it can't hurt)Long rides after a full work day may just not be giving you enough time to rest and relax.How are you sleeping?Overtraining often leads to trouble sleeping and intense exercise late in the evening can affect sleep as well.One solution may be to just cut back on the work LOL