Your hair sounds like how mine used to be, so I'm going to give you my basic routine. It sounds like your hair needs more moisture, your scalp may need extra scrubbing, and you just need to find your magical product combination.
I'm 2a-2b, medium-fine texture.
After about 2 months of this wash and conditioning routine, my tangles disappeared. I seriously almost never get tangles anymore.
Low Poo: Low Poos are gentler on your hair then sulfates, but they still have cleansers that can dry out your hair, especially with how often you wash. I currently use DevaCare Low-Poo. It's $18 or so for the 12 oz bottle, but it works well for me and I've had the bottle for a year now and still have a quarter of it left. I put a little bit on my fingertips and use it on my scalp only
, not the length of my hair. This way, my scalp benefits from the cleansers, but it doesn't dry out my hair. I put a little on my fingertips and then rub and massage my scalp like crazy for several minutes. I then rinse my hair in sections. I lift the sections of my hair and rub some more while I rinse so the shower water can really rinse out the low poo, dirt, grime, dead skin cells, etc. All of this rubbing and rinsing made a huge difference in the greasiness. I am at the point now where I wash my hair twice a week and that's it. No dry shampoo needed either.
Conditioner: I use DevaCare One Condition. My hair LOVES this stuff and it smells better than the DevaCurl flavor. I take a huge glob of it and run it through the length of my hair. I'm careful not to apply too much to the root area though because I don't want it to weigh down. Then I scrunch my hair a few times so my hair sounds squishy. This supposedly helps get the conditioner into your hair. Once the conditioner is applied, I get a wide toothed comb and part/comb my hair. I have a mirror on the shelf in my shower. I used to use my fingers to comb, but my hair would be frizzy, so now I just use a comb. Then I let the conditioner sit on my hair while I shave, wash my body, etc. Then I rinse well and gently squeeze the water out of my hair so it isn't totally dripping.
At this point, I get out of the shower, dry off my body, grab my products and flip my head over into the shower so I can apply product upside down to my wet hair.
Leave In: I have a love hate relationship with leave ins. Can't use them in the summer because they weigh down my hair too much. I find this one to be very helpful for me in the winter though during the dry weather. I use Regis Olive Oil leave in conditioner (not to be confused with their olive oil rinse out kind). You can find it at Regis salons and the salons at Walmart. It's a small yellow triangular bottle. I apply a small amount to the length of my hair (I rake it in, no scrunching yet). The olive oil helps seal my hair. My frizz factor dropped dramatically when I started doing this.
My hair is IN LOVE with AG Re:Coil curl activating cream. It provides hold and the mag sulfate in it boosts my curl quite a bit. I bought the larger bottle with the pump. I rake in about 3 pumps. Again, no scrunching yet.
For gel, I started out using DevaCurl's ArcAngell. Looking back, it dried out my hair, made it kind of stringy, and the wheat protein in it made my head itch. Now I use either As I Am curling jelly or Aussie Instant Freeze gel (found at drugstores everywhere). These 2 gels provide much better definition and clumps for me than the Deva gel did. As I Am is found at Sally's and I use it in the spring and summer when the weather isn't so dry. In the fall and winter, I use the Aussie Instant freeze because it's glycerin free. Glycerin apparently makes my hair frizz out in the winter. I don't use a lot of gel, just a small blob of it to form a gel cast while I dry my hair. I rake in the gel really well too. Still no scrunching.
At this point, if I see more frizz, I'll sometimes take my comb and run it through once or twice. I try not to though if I can help it. I used to try to make a few clumps, but I don't even bother with that anymore. Then I take my curl cloth (tshirt would work here) and slowly scrunch my hair once or twice. That's it.
Then I grab my hair dryer and diffuser and pixie diffuse for 20 minutes or so until it's 90% dry. So basically, I take a section of hair, put the end in the diffuser, and slowly bring the diffuser up to my head and leave it there so my hair dries in a scrunched position. I diffuse upside down and diffuse each section for a minimum of 2 minutes at a time on medium heat, low power. Once all the sections have been dried for 2 minutes, I just start randomly pixie diffusing them again the same way until 90% dry. I keep myself entertained by catching up on my facebook on my phone or reading on my phone, etc. Then I gently straighten up, shake my head a little to get the curls in place, then clip my bangs for some lift while it air dries the rest of the way.
Once dry, I rub a little leave in conditioner in my hands, bend over, and gently scrunch out the crunch.
It seems like a lot of work, but it's worth it for me to have soft, clean, frizz free wavy hair. I hope this gives you some ideas to try. Our hair is all so different even though we're all wavies.