Persistence is not an all-or-nothing endeavor. Just because your persistence breaks down one day, or in one situation, does not mean that all is lost. You’re allowed to have bad days. Just make sure you get back on track as soon as possible.
It is natural to become discouraged and to consider giving up. When that happens, go ahead and experience those feelings. Of course you have doubts. Of course you get weary. Take some time to give consideration to those negative thoughts. They’ve been nagging you, so it is best that you deal with them. Consider their validity. Consider what they’re trying to tell you. Look objectively and realistically at what you’re doing. Maybe a course correction is in order. Maybe you even need to change the destination. Or maybe not.
Then, once you’ve given appropriate consideration to your doubts and discouragement, make the commitment to get yourself back on track. You’ve gotten the discouragement out of your system. Now it is time to move on. You may very well change your approach a bit, yet the key is to keep going. Look at your doubts and discouragements as ways to make you more effective, rather than as reasons to stop.
You will get knocked off track on a regular basis. The key to persistence is in how fast you get yourself going again. Fortunately the value of persistence is cumulative. You can pick up right about where you left off.