System and Network Security Breach Detection/Checkup

Need someone to check my network and systems to see someone somehow got into anything or hacked anything etc. I have had event tickets stolen now ongoing for a few weeks. Not a ton but its happened to like 10 orders from transfers from ticketmaster and ticketmaster is horrible and usually doesnt do anything to get them back. I cannot figure out how this is happening. I dont see that anyone has gotten into any of my gmail accounts or anything. The way that they can be taken is is someone gets the transfer link (which comes into the email account) and then accepts them into another account. But if no one is getting into my email account I am not sure how they are getting these links so I need that figured out.