Well done Bainzy for doing your first plastering job,, your kitchen. It's not un-common to get the odd blemish here and there. As long as you're happy with the overall job, that's the main thing,,, you'll learn from it. It's not advisable to use any type of filler onto bare/new plaster, as you've found out,,, because the suction is high, and any filler wont stick, as it dries out too quick. The best thing to do, is give the wall a mist coat of thinned down "matt emulsion", then give it another when it's dried. The mist coat will highlight any small imperfections, and it is simple to fill them up, because the plaster has now been sealed. I would use a small amount "ready mix joint finish" to fill any blemishes, and then sand it down gently when it's dried out.