Keep Paragraphs in Custom Field

I have a custom field that has text containing paragraph breaks (not with <p></p>, but just in appearance). When I insert the field into my post, it doesn’t keep the breaks but puts everything together as one big block.

Here’s an example of what I have in this custom field:

Lorem Ipsum is simply dummy text of the printing and typesetting industry.

Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.

It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.

but it’s coming out as:

Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.

How can I accomplish this? Inserting the <p></p> manually isn’t an option, as I have many many posts already created like this…