Debo acted strange on walk

For those who don't know. Debo's routine changed a lot. My OH, who's been looking after Debo most of the time flew to UK, he will come back for us in 3months time. So Debo lost he's daddy, he's daily routine has changed as well, we go at differents times. He was fine until today. So on our walk we met his female Labrador friend I didn't know. So I've asked Debo to sit, went to say hello to the labrador, then Debo approched us, she went all submissive, laid down showing her tummy. Debo jump on her and start growling. I've pulled him off her, told him to calm down. After that he repeat it so I've put his lead on. He never acted like that with females. So that was a suprise for me. Two minutes after that we were walking up the hill and Debo spotted men doing some straching, he went all tense, hair, stood up on his back, really unsure, he backed up, started walking behind me and making noises like bark but like he was scared. And he's fine with people. I was acting normal even started singing.
So I was thing, those two incidents could be related to all the changes in his life. Or it was one off, he just had his moment.
I do try to keep everything as normal as possible, to not show him how do I really feel. But I know he can pics up on my emotions. And also he knows I'm not as confident as my OH when there are others dogs around. So maybe he thinks he have to protect me? How do I change that?
Sorry for the long post.

Oh don't worry about the long post, it helps to understand what's happening.

It could well be that he is being more protective of you and the routine change will probably have had some effect. Give it a few days and see if he settles. It could just be a one off event.

Thank you Ian. If he's being protective over me how can I show him that he doesn't have to, and it's me who have to protect him?

If he continues to show this kind of behaviour try distracting him from whatever has got him upset or angry. You could try focus exercises by stopping him, make him sit and focus on you. When he focuses on you reward with a treat. Repeat this whenever he looks like he is going to react.

It might take some time but it works with my Flo, though we use her favourite stick to distract her.

He may have reacted this way because something different happened, the workmen he may not have been prepared for ?? Your OH return here would have upset his routine so may need a bit of time to get used to him not being around.

Agree with all points made , also, how often does Debo see strange men stretching! Must look very peculiar to a dog and hackles up is an involuntary adrenaline reaction so I'd imagine he probably felt quite unsure x

Thank you all, I'm just over worry about him, trying to do my best.

agree with all thats been posted,try and not to worry,easier said then done i know,we all worry about our dogs,it sounds like your doing every thing right by him