Which passwords are you changing? Is it the access password to your device, to your email provider and/or your router?
Does anyone else have physical access to your device?
Do you only make doctors appointments and hairdressers by email? These sound like the sort of thing I would make by phone or text. In which case do you think someone listening in to your phone calls too?
As dragonfly46 suggests, you may have many 'tracking' cookies on your device which make it appear that web sites you have queried are 'following you around'. You can delete your web history but will have to be prepared to add back in your ID and passwords to access sites you want to continue using.
Do you use an online calender/diary for your appointments? If so, I would check the calendar settings and ensure that you aren't sharing it with someone else.
Are you using a computer that has a number of ports available? Have you checked that there are no 'extra' USB type sticks in them.
Why would you be targeted? What could be gained?