I'll expand a little in case you think we are frightfully rude. Most high street shops and online bra charts are still using an old method which results in a recommended size which is actually pretty wildly wrong. A few places do it right, and there are a bunch of us on here who are trying to help as many women as possible get comfortable and supportive bras.
If you truly need a 38A, then I'm sure we will find some gorgeous ones. But when measured and fitted correctly an A cup (any A cup) is actually really very rare. We've probably refitted thousands on here by now, and I think I have seen one person who was a true A. The reason for this is that most big shops are fitting what is basically a bra too big in the back and too small in the cup. So M&S, for example - temple of bra fitting and all that. They fit me in a 36F. I promise you, I am not a 36F. I get fitted at Bravissimo and know bucketloads about bra fitting. I'm (roughly) a 30HH/J. That's pretty far out.
If somewhere like M&S say you are a 38A, then changes are you are more likely a 34DD. I promise, all marbles are intact - they are getting it that wrong. The issues you mention are all classic bad fit problems.
If you have one, grab a tape measure and take your bra off. Measure underneath your boobs firmly (in inches) then lean forward so your boobs are hanging down, and measure around the biggest (so now the lowest!) part of your boobs. This shouldn't be pulled tight - you don't want to squash the boob tissue.
If there is around a 1" difference between these measurements, then you are a true A cup and we;ll start hunting bras! If not - post the measurements and we'll help find you a better fit.