The title pretty much explains it,
What is your biggest losing streak at martingale which you won in the end?
Do 20x martingle and i win 0.05
BTCDo martingle again and i get 25 Redline lose 0.3
BTC 
Lol happened to me once as well , I won 200x at 5k(first try at faucet) and I won. Lol, then a 2.5x completely devastated me.
I think we must stop gambling if we get profit, but that is vry hard, if we get small pofit we will do it again and we dead