Need motivation and tips

Wow! 28 lbs lost is incredible!! Sounds like you need a fitness regimen to switch things up a bit and to get excited about! Maybe signing up for a 5km or 10km and taking on a training program?

28 lbs is amazing for three months! It's so amazing, it's really not surprising that you slowed down a bit. And by "slowed way down," I presume that means it hasn't stopped completely?

With 100 or so left to lose, you can probably expect to see about 1.5-2 lbs a week (give or take fluctuations for that time of the month, and random water gains). Even the high end of that spectrum is less than the rate you have been losing.

Don't dispair. Keep eating at a good deficit, and you'll see the scale trickle down again. It may take a few days, if you're currently experiencing a water gain, but it will go down. Just remember that the best trick for weight loss is being consistent and eating at deficit that is sustainable for you. (Also - don't forget to enter that loss into MFP so that it updates your new deficit to account for your lost 28 lbs).

And throwing in a little exercise isn't a bad idea for regaining the spark of motivation. Just start at a rate that's appropriate for your experience. A lot of people end up starting out too fast and burn out or injure themselves.