Hair Breakage

Are you using shampoos and conditioners with a lot of silicones?  They are usually anything in the ingredients ending in "cone" or "one".   If they are heavy in silicones and that is allowed to build up on your hair, they can break off after many months and take your hair with it. 

Silicones are fine to use if you like them, they do have superior detangling capability. They should just be clarified off every once in awhile.  Get a shampoo that calls itself "clarifying" and use that on your scalp and length, not every day though.  You should not use a clarifying shampoo more than once every 2 weeks to once every 2 months.  They are very drying to hair (but necessary to remove buildup if you're going to use 'cones'), so you will have to condition very well after using them.  Consider a mayonnaise conditioning treatment, or use your regular conditioner twice. 

If your hair has a lot of splits, you may need to consider getting a trim.  Splits will not heal and they will need to be removed or they will climb the hair.  If you don't want too much hair taken off (which salons tend to do if you aren't forceful about insisting otherwise), consider "dusting" your hair - cutting off the splits from each individual hair.  This may not be the most practical way to do it if you have a lot of splits, or give a very satisfactory result (if you have lots of splits, your hair will probably not wind up bluntly cut afterwards), but it is an option.

As for eating, try to go for a diet with more fresh fruits and veggies, not too heavy on the meats or sugars.  Many people who eat western diets mess up their body's Ph by eating diets too heavy in meat and refined sugar, causing various illnesses.  (I'm not saying don't eat those at all, just consider eating less of it and replacing it with milk, cheese and eggs).  This is not going to have a benefit for hair per se, but if your whole body is healthier, your hair and skin will be healthier as well.