There are two types of pain to deal with when gambling and losing.
1. The first one is the money you risk and lose.
2. When the money you almost win is very big.
I am a conservative gambler and careful with my funds, so I would say that the second option is more painful for me.
Although I always have a set budget for my bets and never bet more than I can afford to lose, the idea of almost winning a large amount of money and losing it is much more frustrating than losing the money I initially bet because when I bet, I knew there was a risk of losing and I was prepared for it. However, when I am close to winning a large amount of money, I start to dream about the possibilities and think about how I can use that money to improve my life or achieve my goals.
When I miss out on that opportunity, I feel a sense of regret and frustration because I know I was close to achieving something big... whereas losing the money I initially bet is easier to deal with because I knew there was a risk of losing and I was prepared for it.