Hi ineedamum,
Before I retired I was an HR manager for most of my career. Unfortunately this sort of behaviour is far too common. I agree with Sparkling that he may feel the need to boost his own confidence by putting others down. For those in your situation who came to me for advice, I would have advised the following steps - taken carefully and with respect:
1. Ask for a one to one with your manager and explain carefully and respectfully that when he speaks to you in this way, you feel humiliated (insert appropriate adjective) and that it is affecting your confidence. It may be that he doesn’t know how his behaviour comes across and you will be giving him a chance to rectify that. Discreetly note down what his response is and any advice/requests he proffers.
2. Discreetly start keeping a log - dates, time, what occurred, who else was present. This is building a history and will be helpful if you need to go to HR. Don’t broadcast this to others or you could find yourself open to disciplinary action.
3. If the first point doesn’t resolve the situation, start dropping the buzz words into your conversation. Along the lines of: “when you speak to me in that way I feel humiliated/undermined/bullied” etc. Record these conversations in your log, recording the points as above.
4. If things don’t start to improve, book an appointment with your HR department, they will be familiar with in-house policies and procedures and will be able to advise you and steer you through it. They will also start to build a formal record.
5. Don’t resign, this is your career and worth working for.
In my experience most cases are resolved at stage one. Sometimes a Frank conversation between both parties is all that is required and the other party is surprised, embarrassed and shocked to learn how you feel. Be prepared to act on any points he has raises as well - this can also be a personal opportunity for growth,
I hope this helps and all goes well. If you see obvious signs of stress in yourself, don’t delay in going to HR and seeking help. Often we think we can just grit our teeth and get on with it, but don’t release how close we are to a breakdown or similar sort of mental health episode.