With the stones that other people put in your way, you can also can build a house.
I don't have enemies, yet, I have some colleagues whose agendas occasionally clash with mine. So opponents you might call them, but what I have learned since my spiritual path opened up to me is that they - just as it is the case with my friends - are messengers of the WAY. I have come to realize that no-one looks out for my overriding goals more than life itself, that is, as long as I face every problem to the best of my abilities. So when the so-called opponent arm-wrestles me, I am as curious and open-minded as anyone to find out what will come of it. I know that this conflict - win or lose - will open new doors for me that are perfectly aligned with the WAY.
Anger is always an attack on our SELF. We certainly are all human, so when hateful feelings pop up we have to accept them, but at least we can channel them into productive and creative outlets. Certainly, if the negative energy gets to you, you can always go kick-boxing to let off some steam, but once you have recovered somewhat, please go back to the problem statement and focus all your curiosity on finding the message of the WAY in the dilemma. And no matter whether you win, lose or circumvent the problem, please value your opponent as a messenger of the WAY!