I think the whole confidence thing hinges on not allowing yourself to base your self esteem on others opinion of you.
Sounds easy? Well unfortunately it’s not so simple for many of us. There’s times when we do have to listen to others feedback because there may be valid observations in there. But also the same time we need to get the balance, to know when a point is fair and valid.
For me it’s about understanding my flaws and weaknesses but still believing in myself and working on progress. I’m not totally self confident all the time but I’ve had improvements. I’d say to you to celebrate seemingly small achievements is a great thing to do.
I’m sorry, it must be very hard if your spouse is so critical, it’s something I personally would not cope well with.