don't lose hope, you've already made the 1st step, acknowledging you need to make changes and wanting to lose weight, you've already started working on your diet so congratulations. I've been there, 5 years ago I saw a photo of myself and nearly had a heart attack when It forced me to realize how much weight I had put on after having my son, there was no one to blame but myself, being inactive, terrible food and drinking too much, the next day I joined a gym and committed to eating better. I have lost 30kg and I am now a personal trainer and have never been happier or healthier and I love my life, it can be done.
-Don't "diet", just make better food choices and commit to eating better the majority of the time, there's no reason to eat a whole large pizza to yourself or tub of icecream or block of chocolate (all things I used to do, now I may enjoy them occasionally but dont feel the need to eat until I'm almost sick)
-Stop drinking soft drink, fruit juice etc
-Cut back on the alcohol big time, you've heard of the macro nutrients protein, carbs and fats right? Alcohol is another macro and is the 1st one your body will need to burn off before it burns anything else, so if there is alcohol in your system your food will not be burnt off and weight loss is not going to happen during that time.
- DON'T LOOK AT IT AS 30KG!!! Looking at the big picture is huge and daunting, 30kg is maybe a year from now, break it down to achievable goals, start with 5kg, you can lose 5kg and within a realistic amount of time. Lost that 5kg, cool let's work on that next 5kg or next 1kg. You've lost 2kg awesome keep at it and another 2kg will come off. Slowly slowly they all add up.
-Don't just base it on the scale, get yourself some measurements done. I've been running an 8 week challenge at my gym coming up to Christmas and at our mid way weigh ins almost every single person said to me "I've been working really hard and eating really well but I just haven't lost any weight" but when we did their measurements every single one of them had lost 15-20cm off their body overall.
-Don't let any set backs throw you off, you gain a kilo one day,who cares it happens you cant always be perfect keep at it, you give in and eat every terrrible chocolately thingyou can find, so what that's not the end all be all of your life. Take your good days with your bad and stick to it.
-Final bit of advice, weight loss is mostly diet but exercise helps a hell of a lot. Even if it's just walking to start with try to get out there and aim to get into some group fitness, it will push you, help you achieve your goals ad give you a fun social activity that helps so much with mental health and happiness.
Best of luck
and sorryfor the super lonv response