I started boxing a few months ago but only started sparring one month ago. The coach makes us spar with "limited weapons". For example, sometimes we're only allowed to jab. Other times we're only allowed body shots. When I spar against people more experienced than me, I rarely penetrate their defense and many of my shots miss. When this goes on long enough, I get frustrated and start thinking things like,

"Man, what should I be doing to get to this guy?"
"Why isn't this guy falling for my traps?"
"I wish I had more than just jabs."
"This is getting pointless. Should I get angry or should I just give up? Because keeping up my current pace definitely isn't getting me anywhere. "

Has anyone else felt this way and how do you deal with it? How should I be reacting to these situations?

Sometimes I feel like going all out and try to knock my partner's skull off. But I know that's stupid because 1) it's sparring and i should be working on technique and 2) if I lose my cool, i'll probably play into my partner's hand and eventually get knocked out.

What attitude should i have when losing a sparring match?