Being happy does not depend on your job, it is your internal attitude toward life.
Yes, parts of my job can be stressful, and cause unhappiness, but I choose how to react to it. Sometimes my reaction is quick knee jerk, but when I back off and consider how I want to act, that is my choice, good/bad/angry/swearing/acceptance/determined to work for change.
I like nursing. I (mostly) like my job. I like my life. I get angry and frustrated and sometimes furious about things that go on in the workplace, but I choose to back off, settle down and try not to let any of that slop over into work habits, or how I treat pts and coworkers. Don't always succeed, but there you are, I am human. I have no problem with apologising when I should.
How you perceive your work is a major part of how you react to it. Some work situations are truly toxic, and you will find people on AN who encourage others to find a less toxic workplace, I'm not saying to look at everything with rose colored glasses. Judge the situation, stay or move on, make the choice how to react and what you will do about it.
So my words of encouragement, yes, I like nursing. I find it rewarding.