Low self esteem at work

[unhappyatwork16]

Ive been in my current job for the past 5 years and use to really enjoy it. Six months ago we had a new supervisor and for the first few months everything was great.
In August when I was on two weeks annual leave, we had a visit from higher up management. The visit did not go well and when I asked my supervisor why he said because there were a lot of things not done right in my department, this visit happened on the first day of my leave (so nobody else had messed up) so I took it that he was aiming the comment at me personally.
Since August till now there has been various comments from him about my work he tried to do it in a jokey way but i can tell he's not joking. He has bad mouthed me to another colleague and criticised my work to them.
My manager has told me he has no problem with my work, but I still feel really low in confidence and I'm struggling to stay positive at work. I feel like if I spoke to someone about how i feel they would just think I'm been over sensitive or that I'm over reacting :(
Can anyone offer any advice?

If he has negative comments regarding your work he should be discussing them with you and you alone not others. Have you asked him directly about the exact criticisms that he made behind your back or just asked if he was happy with your work.

Please bear in mind the reliability of your sources too. Some people like to big themselves up by placing doubt in others minds.

If you report to them directly, they need to get specific about your work quality, areas for improvement and a timeframe to enable you to focus your efforts on putting things right.

If suggest you bite the bullet, set up a meeting and say you want to work with them to address their concerns. It may be very difficult at first, because you are asking them to tell you directly what you've done wrong. However it will stand you in good stead because it shows willingness to improve and it will clear the air.

If they obfuscate and minimise the situation, ie they are unwilling or unable to be specific about exactly what the problem is, I would make detailed meeting notes including date and time plus the fact you instigated it, so that if they later try to level criticism or take things to a formal disciplinary you can evidence the details of the meeting and show how you tried to get things back on track.