Need to lose weight!

I moved in with my partner almost 3 years ago and since then I have put on over 10kg. Recently I’ve been feeling really crappy about myself and need to do something about my weight gain. What helped you guys lose weight and what tips do you have? Also what keeps you guys motivated. If you have any apps or anything like that pls let me know xx

Any advice is so appreciated so thank you so much in advance!