What am I doing wrong? :(

So I changed my set today all on my own. The first time it got put in I was at my doctors and she helped me along through it, so today my three days were up and it was time to change on my own. So I followed the book exactly, and before I changed i was at 118, I then had a snack and bolused for it and I checked it about 45 min later and bam! 235! I waited awhile and  tried to figure out what I had done wrong and thought it was my insertion so I took it out and checked again and 258! I then checked for keytones and it was negative so I  changed the set and did the whole process over and put in another one in a different place. The only thing I could think of was, when I was doing checking the insulin to make sure it was coming out of the tube, some of it got on the adhesive the first time, so the second time i didnt let that happen, I checked it an hour later and it was again back around 230, so I gave myself a correction bolus and I checked again and it was only at 214, my husband came home and gave me another bolus just a bit ago and I'm waiting to see if it will get back to normal. I am so frustrated right now because I don't know what I'm doing wrong, I am using the Mio insertion sets, if anyone has any advice it will be greatly appreciated!

Thank you!

Mariah :)