You may be burning yourself out and may not even realize it because you are so intent on an outcome.
When online dating becomes exhausting to you, it may be because you are trying way too hard. People may get that sense when they interact with you on an online dating site and this may actually turn them off.
You may have reached a point where you want to end things with a guy that you met on an online dating site for whatever reason.
Perhaps you feel as though the connection that you once thought was there is now lacking.
Perhaps you feel as though this person has turned out to be somewhat different from the initial impression that you had of them upon meeting on an online dating site.