I've done the opposite! I bought two bottles of conditioner once and was trying to wash my hair (pre-CG)... disaster.
If your hair is very dry on its own, I'd try to remedy that CG-style by co-washing, adding moisture as much as possible, to get the best effect from any styling products you apply after that. Start at the source of the problem.
DTs are very hit or miss for me. Most weigh my hair down, too. I use straight raw coconut oil overnight, and that turns out well. I know people try to avoid it due to protein, but my hair has zero problem with it and I have read various things about how it isn't a protein itself, but instead allows hair to hold on to protein, etc. I've also read plenty of threads showing that people with fine, low porosity hair often benefit from protein. It's no perfect science, whose hair likes/hates protein, you just have to figure it out for yourself... by trying. Gulp! I'm no protein master, but I know what works for me. Things like olive oil and shea butter are disasterous DTs for me. So experiment a bit on a day when you don't have to have good hair.
The Palmers stuff appears to have both coconut oil and coconut milk in it. Coconut milk contains protein. FYI. Again, I'd go with straight up plain coconut oil, so if you have a bad hair day you know "avoid coconut oil" instead of wondering which ingredient did it.
I dislike mineral oil on skin and hair, and won't go near it. That's all I have to say about that.
The Garnier gel did not make me crunchy. When I say "SOTC" I mean "scrunch out the crunch," but it was really more "scrunch to soften the definition." Because I have fine hair, the gel made it super-clump in a lovely way, but then I scrunched softly to make the curls a little "fatter" so I didn't look like I just had super-defined ropes. My fine hair can form like, eight super-curls and leave me looking really funny if I don't keep it softer and a bit less rigidly defined. There was no real solid crunch action. Then again, people have said KCCC makes their hair crunchy, and it has never made mine crunchy. Maybe my hair is crunch-resistant? I don't know. My hair is always bordering on super-moisturized, which I think really helps prevent crunch/etc. - and goes back to the first point: moisturize the hair.
There's a lot of advice on hair supplements if you search for "supplements." I basically feel that hair grows at a certain rate, due to your body's cycles, and pushing it too far beyond that... I don't know, it weirds me out! Obviously that's my own brain's opinion, not any real fact. But they seem to work for a lot of people. I take a Hair Skin and Nails supplement and while my hair always seems the same, I do have to cut my toenails a lot more often... they bump my shoes. I take it to keep my nails from breaking, which they do very easily otherwise.
Your hair shrinks up way more than mine, it sounds like. Mine shrinks 2-3 inches.
Good luck with the routine today! I'm curious to hear what happens. I'm getting my first dry curly cut tomorrow and I'm really excited to see the results.