Hi there, I am pretty much exactly the same as you.
I've lost 32 pounds, and my goal is another 13.2 pounds and I'm finding it so much harder to get it off! My motivation is also wearing thin, as I know I look so much better and am so close to being 100% happy. I dont know why I'm struggling to stick to my diet 100% when i've completed like 70% of my weight loss anyway!
I'm also letting things slip here and there and then get back on plan and I end up only losing a little bit for the week, or maintaining. Its like im on maintenance, yet I still desperately want to lose the last 13 pounds.
Lately I've figured that you just have to take it week by week or pound by pound (whichever you prefer). I work in kilo's, and I find that by setting myself a little reward for each kilo I lose really helps me a lot. For my next kilo lost, I'm going for Lindt chocolate cake and a nice latte..
I've only done this reward for a kilo lost for the last 2kg that I've lost and it has helped me stick more to my diet than what I was. However, still not totally committed.
I must get my butt in gear tho, other wise I'm not going to make my ultimate target by the goal date either.
Try your best to stick to your plan, and make your target by 7 October! You will feel so proud of yourself