I am knitting a cushion cover with a campervan on it (Wendy pattern no 5739). I am knitting the first row that incorporates the campervan itself and it starts with the wheels. It is a purl row, whereby I purl 9 stitches in cream, introduce the purple one to purl 4 stitches for the start of the wheels, purl another 17 stitches in cream, purl 4 stitches for the second wheel in purple and then purl the last 9 stitches in cream. I decided to drape the cream yarn across the back of the purple as I only need to purl 4 stitches in this colour. I purled the 4 stitches with the tail of the purple yarn as well, to secure the end, so the stich was double thickness. I followed an online video clip on how to catch the float made by pulling the cream wool across. I also made sure that I twisted my yarns each time I changed colour. At the end of the row, I then turned the work to knit going back the other way, following the same colour formation. However, the purple stitches are not sitting in a straight line - what was the first purple stitch on the purl side (and now the fourth stitch on the knit side) seems to sit really low down (as shown in the photograph) and looks appalling! I have tried this about 7 times now and each time it looks awful. I have attached (hopefully) three photographs - 1 shows me adding the purple yarn and twisting it with the cream yarn for the first purple purl stitch; 1 shows the cream float caught and the last photograph shows the long stitch. What have I done wrong?