Not sure where you are in the world, but if you're heading into summer your plant should be perking up and doing better... stick your finger in to be sure soil is dry before you water, and skip the miracle gro (or use at 1/4 strength).
If you've been growing it in that pot for a while, it's possible fertilizer salts have built up in the soil. You can flush it thoroughly with fresh water, adding a quart or two and letting it run freely from the drainage holes. Better yet, repot it with fresh, slightly moistened potting mix (not miracle gro, which may have too much fertilizer and retain too much water, especially the "moisture control" type).
Just thought -- Does your container have drainage holes?? If not, it's super easy to overwater. If you haven't been overwatering, a buildup of fertilizer salts is my best guess for sure; it'll happen faster in a pot without drainage. Fresh potting mix and a container with holes will help, in that case.