Yes, losing streak can be very stressful. but I guess by now one should be used to such as a gambler. Most of the time, we have more losses than wins. But since we play for the fun, it actually doesn't hurt much. That's why one doesn't have to be too attached with his games to avoid being depressed. Once you are stressed in gambling just take some time off. It would help you let go, so you don't have to over think it.
I like the phrase "we don't feel hurt much" because even for those who play for fun only, you can't completely say that you don't feel any atom of pain for losing; no matter how little it is, it's painful to lose. The level of suffering that can be caused to you is based on your level of tolerance and the amount you spend, which has drawn on gambling. We approach it with what we can afford to lose and leave when we notice that we are losing too much and when we can still control the pain that the loss can cause us.