If your enthusiastic and knowledgeable about your subject that goes a long way.
Nooo...and from a trainee English teacher, too 
I teach primary and have done for 15 years. My PGCE wasn't particularly bad-though observations could be stressful-but I didn't have that pressure of my own class. The NQT year was hard but the year after was probably worse because you lose your NQT time and it's all just down to you. The next few years were ok; certain times of year were harder than others and I was always shattered by the holidays, but I coped. Then I went part time as I had children; that was great, though SMT still expect plenty from you!
Things have changed quite dramatically though in the last two years. The expectations regarding target setting, assessment, marking and planning are ridiculous and most of the work I seem to do is one long papertrail that benefits nobody but wastes hours and hours of my time. Things have been hastily implemented (badly), never properly embedded and then sometimes just abandoned; p4c, Big Writing/Pie Corbett, Brain Gym, Talk for Maths, Learning Objectives, Success Criteria, 3-part lessonsm 5-part lessons, mini-plenaries, APP, R time, Mantle of the Expert, Seal, MFL, thinking Hats, AFL, Talk Partners, wave 2/3 interventions, ELS, ALS, Springboard, Eric, VAK, VCOP to name a few. Hardly any of these things existed in my first year of teaching primary-and hey, the kids still learnt stuff!
Performance management has become a tool for unscrupulous heads to hound teachers they don't like/who don't pay ball/whose face doesn't fit or who are too pricey out. I've luckily always had good/outstanding obs but in my area, if you get anything other than a 'Good', then the SMT en masse come back to see you within a week-no support, just clipboards. This is repeated until you either improve or you find yourself on capability. I've seen good teachers crushed and got rid of because a new head came along and they just didn't like them.
I love teaching, but I can only survive at the moment because I'm part time. The full timers are either 55+, on their knees and thankful to be nearing pension age or early 20s and either full of enthusiasm (but with no life!) or teetering on the edge of capability. I do not want to live like this for the next 30 years. Most of us feel like we're treading water at best.
OP, I would be interested in hearing what you think of your work/life balance in a year or two.