Being an adult sucks, but you get used to it.
However, one thing I've always noted is the trade-off between money and time.
Part-time work:
- More free time.
- Less money to spend during your free time.
Full-time work:
- Less free time.
- More money to spend during your free time.
Speaking from second-hand experience, it sucks working part-time because although the free-time you get is great, your financial situation limits what you can do during it. And speaking from first-hand experience, having more money is great but I'd be a lot happier if I had more time with which to do stuff that required spending money.
It's a double-edged sword no matter which way you look at it, and I realise this has little to no impact on your actual question but I felt like digressing.
But to reiterate: you do get used to it. It doesn't become better. It never gets better. You merely... adjust.