Fix my existing word press website

I need a WordPress expert to fix my website that has encountered a critical error. The following issues need to be addressed:

– message states: “There has been a critical error on this website.”
– Fix broken links and images
– Improve slow loading speed
– Resolve design/layout issues

As I am not sure how to fix the issue myself and I’m unsure if I have a backup of my website, I am looking for an experienced freelancer who can handle the task efficiently. Ideal skills and experience for the job include:

– Proficiency in WordPress development
– Knowledge of website troubleshooting and debugging
– Experience in website design and optimization

Please provide your portfolio and references of similar projects completed in the past.