Well, another option is to check out dedicated DC Comics fan forums. Sometimes, fans will share their own fanfiction or recommend good ones. These forums can be a great source because the people there are really into DC stuff, and they might know some hidden gems about Captain Cold's love interest fanfiction.
You can start by looking on fanfiction websites like Archive of Our Own (AO3) or FanFiction.net. Just search for 'Captain Cold x love interest' on their search bars. There are often tags and filters to help you narrow down the results to the specific type of story you're interested in.
Some social media groups focused on DC Comics or fanfiction can also be useful. For example, on Facebook or Reddit, there are groups where fans discuss and share all kinds of fan - made content. You can post a request for Captain Cold x love interest fanfiction, and chances are someone will point you in the right direction.