Are you spending too much time looking for a specific record that might not really even help your research all that much? There’s a couple for whom I cannot find their mid-1800 passenger list entry. After some thought, I’m not really certain I need it. I have a good idea of where the family is from in Europe as I know where the husband’s brother was born. I know what children the couple had and where they settled. The mid-1800 passenger list probably isn’t going to tell me where they were from. And after having spent several hours trying to find them, it may be best to work on locating other records. Sometimes it is necessary to realize that it may be time to work on other things.
You can always go back later and try looking for it again. And some other record you locate may help you to find what you originally thought you could not.