welcome to our forum curious!! SOunds like you have alot of questions, I hope I can answere a couple of them for you.
The first thing you are going to have to realize is weight doesn't come off overnight! It absolutely is somthing your going to have to have patience with and you can't give up if it doesn't come off as fast as you'd like to see.You have to have patience. There are SO MANY diet programs ect out there I personally can't suggest one for you. You have to look at them and decide what works best for you and your schedule. I've read most people that loose weight have made up their own "diet" according to what they like and what works for the amt of time they have, ect. Me personally, My diet is...I only eat when I'm hungry. Actually hungry, not deppressed..I try to make the best nutritional choices as possible. I'm not limiting myself strickly, I mean i'm not saying"I can't have this or that" If I want a cookie, I have one, not the whole dozen. If i want a piece of cake I have one, not the whole cake.ect. I do try to get in 8 glasses of water and very little if any pop. I know this way I may loose weight slower than most but this is the way I want to eat the rest of my life. Thats just me though, you absolutely do what you want to do.
I compeletly understand when you say you come home and your tired and you probably just grab whatever is easily accessible. What you can do is get rid of the junk in your house! Another thing you can do is have fresh fruits and veggies on hand that you can just grab and eat. As far as the trainer goes, and again this is just my 2 cents, If you have the time and money for a trainer go for it! But you can loose weight without one just as well probably.