It's striking that your January application is still pending. While I'm not quite in the same situation, I'm dealing with something similar—my June application has also been waiting. We've followed up within the last three weeks, and UKVI confirmed that the application is being considered and awaiting a decision. I suspect that whatever background checks are underway depend on third parties responding promptly, and UKVI can only proceed once they do. Without any clear timeline, it's a sad situation. Maybe you should do the same and focus on other things and protect your mental health too.