Hmm. A few months ago I was in the same boat as you. My hair was literally a puff of frizz unless I took 2 hours to straighten it. Now that I've been treating my hair right I can let it dry naturally without it looking a hot mess! How often do you put heat on your hair? When is the last time you cut your hair? I know it sucks, but if you have a lot of damage you have to cut it. No amount of deep conditioning can fix them!
Since products aren't working for you (believe me, I know how that feels!) you might wanna try natural methods. Before I shower I always put extra virgin olive oil in my hair. I know that sounds gross but it keeps the frizz down so well for me. Just gotta make sure you get it all out in the shower! It will keep your hair feeling very moisturized. You can also try coconut oil, jojoba oil, etc.
And I know this it a lot of info to take in at once, but you may want to try the CG method. I'll link you to the info about it...
Introduction to the no-poo method
Hope I helped a little bit and I hope your hair improves. Don't give up