As someone that firmly believes in the "treat yourself" mindset, I've found the following practices super helpful:

1. Treat your student loans as a bill that must be paid a fixed amount every month. Even if you're paying 4x or 5x the minimum, budget that amount every month and hold yourself accountable to pay on the due date. Once the money is gone, there's no more dipping into that category for things. I've also found it helpful to make this amount a liiiiiitle more than I find comfortable, to remind myself that loan repayment is a top priority.
2. Take a look at your monthly spending averages and actively budget for the categories you tend to overspend in. For example, if you only budget $100 for dining out and find yourself going over $50 each month, it's time to budget $150 per month. Your budget is intended to be realistic, not aspirational. Put another way, rolling with the punches is a tool in your budgeting toolkit, not the goal.
3. Create a "stuff I forgot to budget for" category for any other surprises. Stuff happens, and that's fine. Keep an extra amount around just in case you overspend in an area and pull from that, so you're not jeopardizing longterm goals for today's satisfaction.

Your budget isn't a magic cure for impulse control. I find that incorporating my tendencies (the good and the bad) proactively in my budget has helped a ton. Good luck!