You have to suck first before becoming good at something. Set realistic goals for yourself and work from there. Better to start now then continue thinking about that you can't do it and not trying at all.
Your best bet would be a private script, I don't believe there is a castle wars bot. Some scripters off the top of my head that do private scripts. @Malcolm , @Juggles , @HunterRS , @Rare scripts , @Spider Scripts.
Hiyo I can do this for you, is there any combat stats? I'm at work right now so it wouldn't be until 9pm PST. I'll do 4m for everything. If interested in add my discord : Synthesizes#8363
You can get paid relatively easy for doing something in-game and get a decent rate compared to most jobs I believe. It's tough to see people rely on a game for income because of their government
It might help looking into getting a private script or developing one of your own that completes Tut Island and then does 7QP. I don't believe there's a way to que up scripts though I may be wrong.
Good luck dude, try and bot smart and hope you don't get the cuck from Jagex. P2P has a lower ban rate than F2P but some people get lucky and are able to powermine to 70 F2P via Iron ores.