I was on SSI before husband died now receive widows benefits, What happens if I get remarried, do I get my disability and Medicare taken, or do I get it still?

It won't change unless you want to use your new husbands

How do I change bank accounts for deposit of monthly social security benefits?

Keep in mind, SSI is income dependent. Your new husband's assets can easily cause you to lose it. They count his. And if the marriage should end, you're stuck reapplying from scratch. They don't care if you were approved before. Think hard before you take that leap. You don't want to be left with nothing to fall back on. Trust me.