Welcome and welcome back to being on program. As you can see, you're not the only one who's been down this road, and has learned from that. I love 75lbs in 98-99 then stalled and thought I could do it on my own. I learned otherwise, but not before I gained it all back and then some friends I really didn't need to see.
You're at a good point where you've learned the lesson without having to go the whole road back like I have. (It's amazing the blinders we can put up when we don't want to see things, isn't it?) So the important part is your back on program. Coming here is a great start, and you'll find a lot of good advice from people here.
Good luck with the Tuesday weigh in!