If there is anything I've learned from the last few years, it's that "Not now" is not a bad thing. It actually means "Hold on, you're getting to the good part." Or "I have something even better planned for you." Or, "I promise you'll get there, but this is important for you to experience."
Just believe that when you look back in a few years, you'll understand why. You will fathom what's so important for you to learn, that your plan needed to wait. And you'll be thankful for it.
Just believe that you'll always get what's best for you. Because no matter how good you are at planning, Allah is still the best planner. Because even though you think you know what's good for you, Allah knows best.
Even when you're getting tired of your life and Allah keeps saying, "Hold on," just keep going and enjoy everything that is bearable, if not good, about it. Try your best to find something that makes your life more exciting and meaningful.
So when He told you, "Not now", just wait for another door to be opened. Be prepared to be amazed. Because He is just that amazing.
So yes, whenever I feel lost, I just have to keep my head up and wait for His surprises. Because He never ceases to surprise me with all the blessings. Because He will always be there for me, as always.
I believe all of that, even though I have to keep reminding myself that I can't control all aspect of my life. And that's completely fine, as that is the job of the Higher-Order who never sleeps nor does his believer any harm.
Because everything is going to work out in the end. Why worry?