How do I build a real estate career on trust not commissions?

You have already chosen the thing most people only claim to: your clients' real interest over the quick commission. You understand that trust outlasts any single sale. That is not just decent, it is also, over time, the smarter way to build a career. The hard days will test it, when money is tight and an easy deal would help you and hurt them a little. Holding your standard then is what makes it real. The choice is not made once; it is made every time the temptation returns. Keep doing the small honest things that build a name: the truthful advice, the deal you talk a client out of, the follow-up after closing when there is nothing left to gain. Those add up into a reputation that sends people to your door for years. You are playing a long game, and it is the right one.