Betting without fear

One big issue I have is that despite the fact that what Im doing has started with a balance of $50 and now sits at about $1059 not including the $282 I have taken from the account and put in my bank I still dont really believe this will work long term.
I think the reason I dont believe is because of the various warnings I have read with respect to probability based betting and the use of the Martingale sequence. However my use of the Martingale sequence is carefully controlled and i would add that what Im doing there is probably best described as a hybrid of the martingale sequence.
In the last couple of days I have twice adjusted my bets to the lack of confidence I had in a meetings progress. This can be viewed 2 ways, firstly and example of my own lack of belief in what Im doing or secondly a conservative but long term approach where making smaller gains over a longer term with less risk is more prudent than the short term bigger bang higher risk approach. In both instances this week i would have come out significantly better off if i had simply believed in what Im doing fully and bet without fear of having a losing day.
If I want this to be successful im going to need to get a balance between going hard out and being prudent. the key to that I suspect is more knowledge of the racing game which will come with time.