43 here, I know what you mean. I started with Deedubb's tutorials and have since moved on to regular Roux primarily using Waffle's page here:
http://wafflelikescubes.webs.com
Here's what you'll need to do:
1. The order of steps is slightly different:
http://wafflelikescubes.webs.com/rouxmethod.htm
2. There is a small set of algorithms to learn here, and you already know Sune:
http://wafflelikescubes.webs.com/2lookcmll.htm
Basically what you're doing is replacing your Sune/Nicklas cycling algorithms with seven direct-solve algorithms and learning to recognize the seven different cases so you know which to apply.
Later on (and I'm not there yet either), you can learn better ways to fix your bad edges here:
http://wafflelikescubes.webs.com/orientation.htm
And better ways for doing the final permutation here:
http://wafflelikescubes.webs.com/rouxmethod.htm
Until you're ready, you can continue to use a cycling method at the end which works fine, it's just not the fastest.
Something else, Waffle presents two corner permutation algorithms for the top layer:
Adj Swap / J-Perm / A2 - R' U L' U2 R U' R' U2 L2 x
Diag Swap/NOT N-Perm/A6 R' U L' U2 R U' x' U L' U2 R U' R x'
1. You can do the adjacent swap twice at first before you learn the diagonal swap. Everything in steps...
2. You don't have to use these algorithms, there are TONS of different ones you can choose from.
For instance, I am using these:
J-Perm (4/6): Headlights in front
(R' U L' U2 R U') R' U2 L R
N-Perm (1/6): Any orientation
(R' U L' U2 R U' L)2
This page lists like a bajillion possible algorithms you can browse through if you're interested:
https://www.speedsolving.com/wiki/index.php/PLL
It's educational just to see how many options you have and consider the tradeoffs. Like, this one is 1 move shorter but maybe it has rotations which you don't like, or it uses a weird move like an E-slice that's awkward, etc...
The ones you'll want to be looking at are "Permutations of corners and edges". You're allowed to use algorithms that affect edges because you haven't solved those yet in Roux. The more things your algorithms doesn't have to preserve, the shorter they can be so this is good. For an adjacent perm, you can use anything showing an arrow between two adjacent corners. For diagonal perm, anything with a diagonal arrow between corners. I chose my two based in part on being easy to learn as they are very similar to each other. I'm sure if I eventually get really fast I'll probably revisit this page and shop for new faster ones though based on criteria I have only a poor understanding of today
As far as practicing, what I've mainly been doing is drilling the first two blocks. I just do blocks, re-scramble without finishing the solve, and do it again. I still do the whole solve when I'm doing casual solves and not drilling though. You'll also want to practice the new algorithms over and over to learn those of course.