Running out of Steam...
I remember "hitting a wall" while losing quickly. I would try and grab for energy...but it just wasn't there. A few days or weeks later it just seemed to come back for no reason. I say keep plugging away. Even if you don't hit the gym, just keep moving. The movement of anykind will still cause the weightloss. Projects around the house are a great way to keep it moving. You're not going to get muscle tone (since you're not in the gym) but you should keep losing.
A couple other things. Have a variety of fruits, vegetables, nuts, protein. For some reason when I ate shrimp I would get a boost of energy. It just seemed like my body was lacking something and shrimp had it. Also keep up on the vitamins. Things like B-1, iron, Vitamin A, D, K could be lacking. Just throwing out ideas. Keep your eyes on the goal. Brian

You said it yourself - "I can't give up now. I am too close to the finish line." So think about how far you have come, what you have accomplished, and re-dedicate yourself to exercising regularly and following your program to a tee. Change your gym workouts periodically to keep it interesting and productive. Join a church basketball team or get a pick-up game together one night a week. Just find some things that you enjoy doing to keep moving and burning the calories and exercising your muscles.
Now get your azz back in gear brother!!

The others have given some good advise. I'd say to look back on what worked for you in the past and how it worked for you. Try it again, maybe with some minor modifications.
Good luck and keep on truckin!!!