Peter -
I first want to address this, "I am slightly worried that I’m not going to be able to stick it out, which is also one of the main reasons why I haven’t done anything about my situation until now, come to think of it."
I feel you! You've probably heard this before but being healthy isn't a membership or a contract that can expire. Sticking it out - it isn't all or nothing. If you start a journey and you find one day you've stopped, start again. Some days will be disastrous, tomorrow is another opportunity to be healthy. Don't worry about failing, don't worry about a day when you might not be as healthy as you once were, just try again the next day. It's a lifestyle change, everyone says it and it's true. Every day will be a work in progress so if you want to be healthier just keep trying! It's not about sticking it out, because there is no "out". Just keep trying!
As far as only eating vegetables or non tasty foods ..... Well, you certainly don't have to only eat salad forever but you could count calories or ww points, cut out carbs or sugar, etc. You can technically eat McDonalds and Pizza if you count the calories and stop when you reach your limit. Of course it's better to eat healthier but it doesn't have to be all veggies. You have to do that some days. You have a healthy lunch but you KNOW you want to go out for dinner on Friday night so you count your calories and you save up. It's definitely not all veggies
Maybe ease in to the journey by taking a stroll through your local market and looking at foods you like to eat and examining their food labels. If you love ice cream but find the food label tells you it's bad for you start thinking of an alternative in the store. Frozen yogurt instead? Maybe yogurt with berries and honey, even a few dark chocolate chips, something for that sweet tooth. Start noticing things the food labels like canned beans, tomato sauces, whole grain pastas and whole grain breads, veggies you DO like, seasonings and herbs that can making something boring better. All of a sudden you'll realize you can make yourself a delicious taco that doesn't have to be dripping in grease because you used beans or swapped ground turkey instead of ground beef and you amped up the flavor with cilantro and salsa and hot sauce! Get to know the foods you like, find healthy alternatives for horribly bad for you ones and follow the serving size guidelines! When I worked out at the gym 24/7 I ate pasta when I got home but I measured out the dry pasta based on the food label so I knew I was eating exactly the serving size and I knew exactly how many calories and fat it would be. I would measure out the alfredo or the tomato sauce too and I had a darn good meal! It might sound like work but the more you do it the more natural it becomes! If you find you are serious about reading food labels and watching serving sizes invest in a food scale one day. It's a great help, especially when controlling bad for you things like cheese!
As far as exercise ..... It's necessary too but maybe start by eating right and see how it goes before you drop a lot of money on a membership. Start taking more walks and using the stairs more and ease into. Once you start eating well and maybe losing some weight you'll feel more comfortable about heading to the gym.
One last thing .... As far as the trauma? Well don't expect the world and don't kill yourself if you fail one day. Don't beat yourself up. If you have a rotten day, move on. Tomorrow will be a good day. If you find yourself binging and realize you hate yourself for it while you're about to shove a piece of cake in your mouth then just stop! Just shake it off and keep going. It's traumatic to feel like something isn't working but every little bit helps. Helps to build good habits, heal your body, improve your happiness etc. Just don't give up on yourself and know it takes time and it does take effort but it gets easier!