Thank you for sharing your story! I enjoyed reading it very much.
I am a 100% f2p as well. Been playing for a year; and although I have never achieved your level of accomplishment, I am doing pretty well for myself and having a lot of fun in game. I think attitude is the key. I have a very laid-back attitude. I play this game for fun and relaxation; NOT to chase after every single fancy hero. So I do not have high expectations and appreciate whatever hero I get. On the other hand, if your goal was to get all the HOTM, then yea, you would have to spend a lot of money. And the more you spend, the more disappointment you are likely to get.
I applaud you for having such a positive attitude, friend! Keep up the good work!