Email problem

I can't access my emails for the past three days neither via webmail nor on my iPhone. Technical support have tried to assist, I've phoned about 10 times, sent DM, updated antivirus and scanned laptop with no issues found, technical support changed password tonight. Received 2 reference numbers. No one gets back to me. Emails still not working. It keeps saying 'session timed out'. I'm getting desperate. It's compromising my work, my banking, everything. I've had this email address for years. Each person at technical support has a different story but no one can resolve the problem.