How do I stay motivated?

Almost 2 years ago I worked out religiously. Everyday for 2 hours. I went from 180 to 140 in just 4 months. Since i got married last Februrary I've gained so much weight, I'm like 200 pounds now. I hate it. For our anniversary this year we are going to the beach in August. 
My apartment complex has a very nice gym and it's free for the residents, I just can't get myself up off the couch. 
I want to loose so much weight I'm just not motivated enough :(
Any tips?