Hi Liz, and welcome
Your story reminds me a lot of myself - I have been overweight/obese for as long as I can remember, and I actually started my journey here at a higher weight than you are now. I've found this site to be really helpful, and everyone here is really friendly and supportive.
If you're looking for information on portion sizes/calories etc, a lot of people suggest using Calorie King (http://www.calorieking.com.au
) for nutritional advice and diet plans. I haven't used it that much, but I've been looking some things up lately and it's a really handy and useful tool. Interesting too - sometimes you think you're eating well and doing the right thing, only to find out it's higher in calories than expected!
I've tried to lose weight numerous times in the past, and this is the only time I've been successful. I think you really have to be in the right frame of mind, and doing it for yourself and no other reasons. It looks like you're ready to take that step, and I wish you all the best!
Feel free to drop me a message if you need anything along the way, i usually post in Personal Progress.