Getting bigger boobs?

So I’ve been randomly loosing weight and i have no clue why! Ive even been to a doctors about this and got a blood test and it’s stable. But my boobs have gotten smaller when i got measured it would always be like a 36DD and my sister size was a 34DDD. And now all those bras are huge. I probably dropped to a D or C not too sure i need to get remeasured... anyway how can i make them grow a little bit? Im trying to gain a bit of weight back and also want to try fish oil vitamins too (I’m trying to figure out what store brand would be the cheapest.) I know this is kinda ridiculous but having the larger size was kinda a staple for me in my friend group so i really don’t feel like my self. I’m still kinda big but not the way i used to be and i have no money to get them done so i kinda wanna get them bigger naturally. I know people are gunna say “you don’t want them big!” But when they were big i really had no problems. I also do cosplay so like how i said it was kinda my thing in my friend group my friends would always make complementing jokes that i had the perfect body to cosplay anime girls lol. I just kinda miss how they used to be