If you're struggling with being overconditioned you could probably do without the cowashing. There's tons of low-poos that are well liked:

SM poos (I would recommend Coconut/Hibiscus for fine hair; some like the Yucca. The Moisture Retention one may be a bit heavy)
Yes to Cucumbers
Giovanni poos
Komaza Care
Free and Clear (good if you tend to be allergic/sensitive)
some like the CJ Gentle Cleansing

Look for low-poo reviews in the products tab of this page!

Everyone is going to react a little different so to a certain extent you won't know until you try. From personal experience: I love the SM Coconut/Hibiscus one. The Giovanni ones are good too my favorite being an older formulation of SaS. I tried the Free and Clear before passing it to my mom and that's a good option for people who may not be able to take 100 botanicals in their hair products. I've turned into a bit of a low-poo junkie so I'm going to pick up the DermOrganics one and YTcuckes.

The ones that were recommended to you are probably worth a shot. Besides staying away from sulfates and other harsh surfactants I also look for low poos that don't have c. betaine as the second ingredient... it's kind of harsh for me, but I can take it in lower concentration. Hope this helps!

What Makes a Cleansing Ingredient More Harsh or More Gentle?
fine - normal porosity*?- medium density - normal elasticity. Hard water. SoCal.
*Used to be low-porosity, but I lightened my hair 1-2 shades, so I may be normal-porosity now.

New climate! Current favorites:
Low-poo: CJ Gentle Cleansing Shampoo, Giovanni SaS
RO: V05 Kiwi Lime
Styler: UFD CM (old formula), FSG + CNPF
PT: CJ Repair Me, IAgirl's gelatine

Experimenting with: JC Confident Coils, JC Rockin Ringlets, CJ CIAB, gelatin gel

iherb discount code: CFN646