You can’t actually fix hair that’s been damaged. Do the swim cap and conditioner thing to prevent more damage from occurring from the chlorine. Stop using 2-in-1, that stuff’s awful for long hair. You don’t need super-expensive salon shampoo, but jumping from the Suave/V05 price bracket ($1-3) into the Aussie/Garnier Fructisse ($4-6, when not on sale) one makes a shocking amount of difference. I discovered in college, no lie, that there is no practical difference between orange-scented V05 and orange-scented dish soap. It does indeed clean really well, but it does so by stripping everything that dirt could conceivably cling to off of the surface of your hair, including the natural oils that you really, really need right now. Even going with the store brand pretend-Dove or pretend-Herbal Essences will help a lot.
In order to make the damaged hair easier to work with, you might actually try washing it less often – if you shampoo daily now, try alternating days of shampoo and conditioner with days of just conditioner. I’d also suggest using an after-shower conditioner in addition to the in-shower kind. Garnier Fructisse has some that’s cheap, sold at Walgreens/CVS, and has avocado oil in it. They advertise all kinds of wacky things on the label, but the one thing they never bother to put on there is that after-shower leave-in conditioner functions as a dandy detangler, which is essential if your hair is in a state where hitting snags while brushing it out might break it off.
Try to never comb it out when wet, even if that’s what you did before. When your hair is healthy, it might well have enough resilience that combing it out went doesn’t hurt anything; now it’s damaged, and you don’t want to do anything that pulls the cuticle open if you can possibly help it. The surface of your hair is really lots of tiny keratin scales, that cling to each other a little like the fronds on a bird feather. Run your fingers down a feather from root to tip, and they stay mostly engaged; run your fingers from tip to root, and the feather turns into a wonky mess. When hair is sufficiently damaged, every direction is the wonky-mess direction.
If “not doing anything fancy” with it means that you pull it back a lot, I’d also invest in some high-quality hair elastics. Cheap elastics catch on hair and snap it off as you pull the ponytail or end of the braid through, and the problem gets worse as more hair breaks off and the ends poke out in odd places. Try some of the soft woven ones with a fabric-like finish for braid ends, and hooks or bungees (http://goo.gl/Qdvlf) for ponytails. A lot of bun clips, alligator clips, and snoods aren’t big enough for hip-length hair, but if you want a simple bun, I find the large Hairigami snap-bracelet things (http://goo.gl/dKeBH) work surprisingly well on mine.
Failing that, if you grow to loathe having to take care of damaged hair, post a picture of yourself here and ask for suggestions on short haircuts. I believe the last person who did so got a look-over and advice from Eve, who is the sine qua non of classy fashion advice around these parts. Better assessments simply cannot be had.