Urgent Vps Server Restoration and E-commerce Website Troubleshooting

My e-commerce website is currently down, displaying a '502 error' or no response at all. I am also unable to connect to my VPS via Putty, receiving a 'connection refused' error. This issue occurred after I, a non-technical user, attempted to restart the server by typing 'restart' in Putty. I have tried using the control panel to stop and start the server, but the problem persists. My shop has active orders and customer photos, making this a critical and urgent matter. I need an experienced freelancer to diagnose and fix the server connectivity and website functionality immediately. The ideal candidate will be able to provide clear, step-by-step instructions for any necessary actions on my part, as I am not familiar with Linux commands or server administration. The goal is to get my website back online today.