How do I manage to do this?

At your height, 45kg is 'underweight' in BMI terms. Right now, you're in the 'Normal' range. So, no, people wouldn't call you overweight, because you're not. I'm shorter than you and after successfully getting down to 54kg, Covid kicked in, my routine changed, I (eventually) realised that I was actually burning more from all my walking than I thought but, conversely, I wasn't snacking on all the goodies at work, because I wasn't in the office - and suddenly I was down at 47kg. I looked dreadfully thin and clothes hung off me. As the world started opening up, multiple friends commented that I needed to put weight on. I'd already realised that myself and have gone back to the middle of 'Normal' BMI where I'm now happily maintaining. Being underweight isn't good for so many reasons. If you want to risk hair loss, brittle nails, heart failure and more, go ahead. I'm assuming you don't want that though.

What you probably need to do is to tone up. That's not going to happen in two months either, but over time you'll look leaner, better proportioned and will still be healthy. Look at the Fitness and Exercise threads as there's a lot of good info there. Specifically, check out the lifting threads - that's not just for bulking up. I know it's not what you want to hear, but you don't need to be having a bad relationship with food and diets.

As for your visits to Sainsbury's, look at the lunch section - they have hard boiled eggs. Or look at the cereal bars and get one of the high protein ones. Eat Natural's peanuts & dark chocolate and their peanuts, orange & dark chocolate bars are approx 200 cals per bar but have 9g of protein which will help you feel fuller so that you're less tempted to snack. (I can only find the 'orange' ones in Sainsbury's - Tesco's don't have them). The fact that they have chocolate in may help you feel that you're not missing out with your friends.

well knowing you’re 18 makes a difference. I was wildly impatient for everything to start happening at 18.

Listen to what you’re saying.

“I want to lose quickly and visibly”, and then you say you know that’s unhealthy and unlikely.

”I want to lose in specific places” but then you confirm you know that is unlikely.

“I have major commitment issues”. Well, at least you’re honest with yourself, plus, don’t forget….only 18. 😇

can you reframe all of this in to something you can do, healthily?

I’ve got two personal references I can give you (even though I’m old enough to be your grandma!)

Don’t shoot for a very low weight. I lost from obese to too much, and became skin and bones. I’m 20 pounds or so heavier than my lowest weight right now- but still wearing the same size? How? I started doing weight training, and built muscle. I’m not PopEye. You wouldn’t look at me in street clothes and say “wow, she’s jacked!” But you might spy me in workout gear in the gym and think,”dang, pretty fit for an old gal!” You’re not going to end up looking like a bodybuilder (unless you want to be a bodybuilder.) that takes extreme dedication, crazy hard work, and hardcore attention to nutrition and timing of cuts and bulks.

But you can vastly improve what you’ve got by strength training.

Second, I had those same big breasts as you. They made me question everything about myself. No one saw me. Their eyes went first to my boobs. They had conversations with my boobs. I swear I had a couple of customers who thought they had standing appointments with my boobs. I spent years humiliated by something I had zero control of.

In my very late 40’s I got a reduction. If I’d know what a change it would make in my life (and my back pain) I would have done it in my late 20’s.

My dear daughter has the same issue and I’ll give you the same advice I gave her. Wait til after you’re sure you’re done having kids and then do it. Nursing your children is the greatest gift you can give them, and the heavens above have ensured that’s it’s likewise a gift to you. There’s no greater bonding experience than nursing your child. Don’t risk that by having a reduction too early.

Even if the doctor assures you it won’t affect your milk, just be patient and wait. But if that’s the route you want to go- and won’t lie, it’s painful and expensive-do it sooner rather than later.

My reduction did wonders for my psyche. I hear in your post the same frustration and disgust I had with my own body because of the boobs. I wish I’d had a stronger personality and could have just flaunted them, but ugh, you understand.

Weight loss helps a few people reduce the size of their boobs, but very few, from what I’ve read here, if that’s a reason for thinking you need further loss.

I will say, thanks to the reduction and the subsequent weight training, I’ve got better boobs now at 63 than 99% of people on the street (no friend requests, you clowns.)

Hugs (the eyes up kind) to you, baby! 😘

as to train and sweets- I often visit a local coffee shop with friends.

Tea or black coffee- 2 calories at most.

See what’s available and make better choices. For example, scones (and I make them from scratch so am pretty familiar with the ingredients) have about half the calories of a light but buttery pastry (at least here in the US).

forgo the clotted cream and just use a lick of jam if you need something on it

Pret- a falafel salad sans dressings under 300 calories. Doesn’t need dressing- it’s already got hummus and pickled veg in it for flavor.

As doofy as it sounds, Starbucks has the highest calories and they are good about sharing nutritional values. When you’re lined up for a treat, open up MFP, and search Starbucks scone, Starbucks almond bearclaw, Starbucks chocolate croissant. You’ll get a quick idea of which is lowest calorie.

After a while, I find that the black coffee alone is satiating and I don’t even need the pastry (or blow to my checkbook!)

And you don’t owe an explanation to your friends about why you’re not getting a pastry. Just do it and say nothing. That’s their guilt trip, and they shouldn’t be issuing you tickets to ride along.

Friends are the worst for trying to keep you at their level, whether they have an ED or need to rationalize two pastries and a sugary coffee.