Hey man, i read the forums here every 2-3months or so and normally dont comment on anything, but i think it might help you. Seems like you have been trying to become a professional (think you wanna quit your job if you reach the right stakes, right?) for quite some time now, like 2 years + you have been playing poker for10 years now, right?
I have no idea about your financial situation, but if you live in Austria you need some money to cover the essentials of living. That said, I would suggest that you safe up money from your job so that you can live comfortably for like 1 year without having to cash out from your poker winnings one single time. Safe the money on pokersites to build your bankroll. That said, I think that there are some other things you might want to consider.
- I would strongly advice you to stay away from rush and cash on gg poker, even if there is no traffic on normal tables. I saw your monthly samples and I think that it doesnt make sense for you to play that format, because a) you are not remotely close to putting in enough volume, b) the volume wont get you on the leaderboard where you would like to be to make extra cash, c) you wont produce enough rake to climb in the fish buffet fast enough to get more moeny out of that and, most imoprtantly, d) if you play higher than PLO10, the competition becomes tougher. Once you go above that, people are playing for a living and take the game very seriously. Again, stay away from that.
Also, I think that i read (not 100%) that you think that your winrate decreases by roughly 50% if you go up in stakes. So if you have a 40bb/100 on PLO5, that would mean that you can beat PLO10 for 20bb/100, PLO20/PLO25 for lets say 10 and PLO50 for 5bb/100. If you go to PLO100, that would mean that you have a 2.5bb/100 if i got what you mean correctly. Honestly, I think thats not true. If you come to a limit like PLO50, there are good regs and I am quite certain that you cant maintain a positive winrate at that limit, which does not mean that you will not be able to do that as a professional of course.
- Why play on ggpoker at all? It seems that it is going way better for you on win2day, so just stick to that and drop ggpoker 100%? Do what's best for you winrate, seek for the softest competition you can find and stick to brm. Dont take shots when there is no action, rather play lower if there is any action. There is no point facing different opponents on higher stakes if you are not rolled for that or having enough money to take a serious shot.
- I dont think there is much value in reading poker books. Idk if I am allowed to mention any products here, but i think you know what i mean if i say that a sub to a leading PLO training sight might benefit you greatly. Dont only go through a 10 week transformation and dont only watch a couple of other courses that might say how to beat this and that limit blah blah blah. Rather stick to the real deal, learn how to play 3bet pots, how cbets work, betsizing and so on as their are courses dedicted to only that. Practice quizzes and see + understand why a hand is played like its played. Do all that and revise it over and over again until you have it down cold.
First, focus on situations that happen most frequently, in your case startin with pre flop game makes sense i think. I saw that you posted some hands and 4 of them should have played differently pre flop. Dont deviate from these ranges and do not make up your own ones, bc they are made of certain rake environments.
I also saw that you came up with some ranges in other threads, Idk where you got them from, but I would also strongly adcive you to stick to GTO solutions in certain rake environments (included in training sites) and stick to that. Pre flop cant be exploited if you nail it close to 100% (not taking into consideration to get 3bet more often bc villain or player xyz folds to cbet to a certain % blah blah blah)
- If you wanna take it really seriously, try to get a coach. Best would be someone who plays plo200+. Idk their h/rates, but i can imagine that it is not that cheap. Maybe you can, if you focus on poker 100% for a year, make a deal with them and get coaching for profits or something. In case you manage to find someone, stick to what they tell you 100%.
- Does it have to be PLO? Or would you also be willing to try out other formats? Maybe there is more value in another gametype, maybe tournaments, idk. At this point i think its fair to say that you can still experiment with a lot of stuff, put some volume in and then decide on what you wanna be doing all day long for 1 year.
- If you should choose to go for it and try to become a professional for 1 year (implying that you have enough money for yourself + resources that you might need to up your game), forget about going out on the weekends. Take one day off a week at max. Work out, eat healthy, start meditationg. Do everything in your power to feel great and maybe start journaling, maybe even here in some blogs.
These are not meant to be any points of critique, I just want to help you to succeed in poker. Wish you good luck at the tables 
edit: I forgot to meantion 1 thing. I do not know if you already do this, but have you ever considered playing PLO MTTs? They are incredibly soft and some good money can be made there.
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Best thing you could do in my humble opinion is to set easy goals (since your not in a rush it seems anyway).
hands beside to obvious made hands and draws, weak-pair+gs too.