Medical Negligence Claim - Delayed Diagnosis Review

I suffered a delayed diagnosis of a serious condition in 2022 at an NHS hospital in England. The delay resulted in my needing more extensive treatment than would have been necessary if caught earlier. I have medical records and a supportive consultant's report suggesting the delay fell below the standard of care expected. I'm not sure if I have a viable claim or what the process involves. I need realistic advice on whether to pursue this and what to expect. I've never done this before and want to understand my options without committing to expensive litigation immediately. I'd prefer to speak with someone who can give me honest guidance on the merits before we discuss costs.