Ok stop kicking yourself. I find that if I weigh myself on different scales I get different readings. It is also a fact that if you weigh yourself in the morning versus night you can have a two pound weight difference. You can also weigh more after a workout. Your scale may be right and the Y's scale may be off. Just stick to one scale.
Remember to that muscle weighs more than fat so if you are building muscle mass the scale can show an increase even if you have lost fat.
It's easy to kick yourself when you're trying to lose weight. Relapses happen. At my worst I weighed 256.5 pounds and was wearing a size 22. I struggled with breathing sometimes when I went up steps and was trying to keep up with my husband. I was embarrased with how I looked and did not have a lot of friends who had the struggle with weight like I did.
At my best, I was down to 179 pounds and wearing size ten or twelve pants. Now I am up to 209 pounds and fighting again to get off the weight. Ultimately, what worked for me was Weight Watchers(WW). However, since living in Korea this past year I have not been able to do WW. One of the things I love about WW is that you really have a support group regardless of if you have a bad week, a so so week, or a good one. They are there for you because they have been through it and I just don't mean the group leaders either. I am not someone who does as well with weight loss on my own. I am greatful I have an amazingly supportive husband but I also had WW friends and a fantastic group leader. I will go back on WW once I am back in the States.
If you are really going to try this on your own it is best to have some support and go see a nutrionist. If you can find a good nutrionist, then they should be encouraged if you are honestly trying to change your life. HOnest is the best policy with the health care people.
As for being tired, maybe you are feeling tired because you are not eating balanced meals. I had a ton of energy once I was eating balanced meals and working out.
Hang in there you can do it. We all have relapses from time to time but the important thing is to admit that we fell off the wagon and to climb back on again.
Best of luck to you.
H