First off, congrats on how much you lost!

Even though the scale is being stubborn now, you've lost a lot of weight and that is definitely something to celebrate!!! Best advice is to not give up and get discouraged.

It's so hard when the scale seems to be working against you, but if you stay on plan you will reach your goal.
I'd suggest setting yourself a goal like to complete a fun run or something, whatever it is that rocks your boat, to provide some external motivation. For me, it's all about mini-goals (and not just weight ones). When I focus too much on weight loss it's soooo easy to get discouraged, so I've been trying to focus on other things, like completing a 5k race this spring/summer. Plus, days when I'm feeling sluggish and want to be lazy I remember the 5k and it helps to get me moving and stay on plan.
I absolutely believe that a lot of my success is because a lot of my focus is taken up with achieving THOSE goals, so that weight loss became secondary. Also, when I first changed my lifestyle and started losing weight I did not weigh myself. I went months without seeing the scale and it helped me stay focused on getting healthy, not just losing weight. Good luck!