Welcome!!
I was thinking maybe you arent getting enough calories. A man needs more calories than women do to begin with due to a higher percentage of muscle than we have. Then you are also doing a lot of working out. If you really are only eating 1800 a day your body needs much more than this to keep it going and its almost in starvation mode. I would check out
www.room42.com they have a basal metabolism calculator on the bottom of the page you can click on to get the amount of calories your body needs just to keep it moving each day. Even if you did nothing but lay on the couch all day your body has to have the "basal metabolism" needs met to keep it running.
(heart beating, lungs breathing, etc..) Your basal needs may be 2200 or 2400 a day. If you are only getting 1800 your body is feeling like it's not getting enough and its slowing your metabolism down until the calories increase. Just my opinion, but I would look into it.
Also what nasus said makes sense too. If your measurements are getting smaller even though the scale isnt budging like you want, you could be gaining muscle and losing fat and the scale seems like its going nowhere but you are actually making progress!
good luck and let us know how it goes!
laura
PS-congrats on losing the 33!!