A quick questions for the successful affiliates out there: How did you start to enjoy the process of testing new campaign ideas when first starting out and still losing money?
I think that successful affiliates start having success when they switch their mindsets from trying to make money to something else, such as thinking of AM as self-improvement or something like that which makes the affiliates concentrate more on enjoying the process rather than the money.
With me, after failing so many times my first year trying to make money online, I just HAD TO change my mindset from trying to make money to "try to become a stronger and better version of myself by failing a lot" to be able to keep going. Of course the end goal was still getting money, but I was enjoying myself more when I kept the mindset of "getting stronger & better" after each failed attempts. After about 3-4 months of having that mindset, I started making money and was able to start my affiliate journey here with STM 
The same thing happened with my pick-up journey. I was having really limited success with women before when my sole purpose of talking to girls was to sleep with them. I started having massive success with girls after changing my mindset from "trying to sleep with girls" to "1. Get as many rejections from girls as possible so that I can to become stronger and better and 2. To try to understand each girl I'm gaming so that I can understand more about female psychology and thus, improving my chances with the next girl I meet."
So what kind of mind shift did you have before you start hitting a successful campaign? Or was there no mind-shift at all?
Very similar to your pick-up journey, actually. Approaching AM budgets as "OK, here's my training budget, I'm going to spend that on data" rather than "OK, here's my budget, I MUST BE PROFITABLE WITH IT NOWNOWNOW!" was one of my big breakthrough moments.
It wasn't immediately followed by regular success, but it was critical in getting there as it gave me the calm and patience to evaluate data.