If you are thinking about it and openly discussing it, that's a positive start! My fiance and I (I'm 26) were the SAME exact way, but we started taking baby steps and so far have lost 90 lbs between us! (since Dec.)
Maybe starting small would help, choose ONE thing to change (no more soda, or drinking enough water each day), and stick with it for a while until you feel comfortable adding one more small thing (daily walks after dinner or a salad for lunch). It doesn't work for everyone, but we decided to eat what we want each Saturday, it helps us stay on track throughout the week and we look forward to cooking a special meal together each Sat, or eating out. You can do this! If you have myfitnesspal feel free to add me for support.