No Fascinating Story Here

I should start by saying that I'm not wildly entertaining or totally witty, I'm just me. I'm a 26 year old mom of one 3 year old little boy that I love & adore, and he is the reason I'm here on MFP. Luckily, I don't currently have any known health problems (had my gallbladder removed in March 2014). However, I am well aware that that could all change in an instant. Being overweight makes me worry that I won't be around for my son as we both grow older. My biggest issue is mostly snacking at night. I get very busy during the day, I often won't eat but snack throughout. Then the evening time comes and after I put my son to bed I start in on my homework (I am a Senior at Northwestern State University majoring in Addiction Studies). While doing my homework and finally winding down, I start to realize how hungry I am and eat eat eat. Then I usually follow that with falling asleep all over my books shortly after. Before my son I was a good 180 at 5'9. Then at the birth of my son I weighed a whopping 239 and over the course of three years as a stay home mom, I added on some extra weight in the form of 30lbs. It's not that I don't know what to do, I've lost 40lbs in 4 months last year, then got depressed after my son's father/my boyfriend of three years left in a very devastating way, I was still in school full time, and I had just started back at work full time. I got lazy and felt hopeless and undid all my hard work and then some. So now here I am trying to get it off and keep it off this time. I believe I just lack the motivation and will power to get it done!
So here I am, with 115lbs to lose, and I'm looking for other friends with a long ways to go, those who have good experience, and even some other single mamas. I just want to build a good support system, I'm hoping this post will help me rally that up. Below I have provided some pictures that help tell a little more about my gain over the past few years.