Measurement check! current wearing a 36DD

Loose Underbust: 31

Snug Underbust: 30

Tight Underbust: 29

Standing Bust: 38

Leaning Bust: 42

Lying Bust: 38

Just attempted to size myself for the first time!! Dont know if I was 100% accurate but the results from the calculator said I should start with a 30I or 32H. For the longest time I didnt even wear bras or at most would throw on a sports bra. I started avoiding that bc of the tension headaches I would get from sports bras digging into my shoulders. I recently just bought some bras from victorias secret and got a 36DD. I know theyre not the best brand but Im on a budget and not in a place where I want to splurge crazy on bras currently. The calculators results just feel off to me, the 36 DD band sizing fits me perfectly it seems but I have some spillage in the cup quite frequently. I do also want to mention that I gravitate towards favoring the balconette bras with how they look and comfort wise typically. Curious if I should try a 36DDD from VS or go up to a G cup and adjust the band? Idk Im lost and rambling but hoping someone can help 💗