Pattern is in the round but I'm doing it straight

I’m doing a baby hat that said to do in the round but the stitches wouldn’t fit around. So I’m doing it on straight needles. with St.st. you have to do one round in knit and one in purl. The hat calls for all knit sts. now I’m at the decrease and all of those rows are in knit stitch. So what do I do now. If I do each row in knit won’t the top look strange with purl showing? I need big time help our 1st grandbaby is due in a wk. and there’s applique to do yet!
I know I can count on all of you as Y’all always come through for me. Big Thanks, Judy

You just continue to knit in stockinette - one row knit, the next row purl. Just decrease on the knit rows till you get to the end and then decrease on purl rows.

You have to adjust from round to flat knitting. In flat knitting stockinette stitch is accomplished by knitting one row and purling one row for the pattern. In the round, you knit all the rows to achieve stockinette. It has to do with the fact that you’re not turning your work in the round, so it comes out differently.

So, when switching from round to flat, you have to figure out which stitch you want to achieve and do what you need to do to get it. If the hat calls for stockinette and says knit every row, you’ll know that the st. st. is what’s important, so you’ll knit one row,and purl one row.