WooCommerce Performance Troubleshooting Needed

My WooCommerce store has become painfully sluggish: pages hang for seconds, the site drops offline unexpectedly, and every so often it throws fatal errors that crash the whole shop. The core goal is to restore fast, stable performance without breaking any storefront features... (Budget: $30 - $250 USD, Jobs: MySQL, Performance Tuning, PHP, Web Development, Website Audit, Website Optimization, WooCommerce, WordPress)