Physical job and weight loss?

[Akolades]

I've hit a rut in my weight loss.

I followed a better diet and dropped from 267 to 239 over 6 months. I'm 5'11, so I figured i should be around 170-190 to be healthy.

The problem is, I've been working at UPS, which is a very physical job. During the first week, without a change in my diet, I dropped down to 230. But the following week, the weight all came back. It's an evening job.

So I was wondering if there is anything different that I should be doing in order to lose weight. I haven't done a specific workout plan, because i assumed that the work at UPS would be enough, but it has not been.

Is there a certain workout routine i should follow? when should I workout? Is there a diet that would be best for this? Keep in mind that from 6-10pm every night, i still hav to be able to perform my job.