Latex underwear too tight?

I search on the forum and I couldn't find a thread or a post related to one of the problems I'm facing. A few months back I purchased some latex underwear (was for women but it was on sale) so I decided to try it out. The size was "correct" and it had a hole in the ass:
   

So when I tried it out at first it was a really good sensation and it was my first time with latex underwear (even if it was for women) but after a few minutes I started to feel little uncomfortable with my balls. So I noticed part of my testicles were hanging through the hole and it was very tight but because It was my very first time I decide to keep the underwear a little more and even I cum with the underwear still on me. But after that I started to feel a little pain in my crotch area and I think it was "normal" because it was very tight. So few days the pain was almost nothing but I feel uncomfortable while sitting down or sleeping on the side. So later I decided to buy other latex underwear but this time for men (without the hole in the ass). The thing about the men underwear is that it has a "built-in space" so the penis can fit correctly? I don't know how to describe it in english, sorry.

So when I put the underwear I still feel it was very tight (I know the latex should be tight) and hurts a little when sitting down, but the question here is those who have catsuits, underwear or something very tight in your crotch area have pain or is uncomfortable later? You get used to it and then it doesn't hurt? 

Thanks (I need to practice my english) 

You should not get any pain from wearing the latex.
There is a major bundle of nerves and blood supplies that run through that area. It sounds to me as if when you were hanging low out the hole you effectively rubber banded your sack a bit.
The only time I've had similar is from a tank top surf suit that has a hole and a pop off codpiece.
Unfortunately the hole is set a little high for me so it leaves quite a bit of tension behind the sack.
Never had an issue from any of my cycle shorts or catsuits

[Like Ra]

OK, let's separate two things. Tight clothes can:

1- cut in
2- compress

The first is never good. If something cuts in your skin, and leave marks afterwards, you need to rethink your bondage or your clothes. The garment can be too small, the seams can be not elastic or not soft enough, the balance can be wrong, etc.

Now to the second case. Compression can be both good and bad. It can help to support the blood vessels or part of you body (think of medical compressing and support clothes), and it can feels good and arousing. Too much compression and you will have the same (if not worse) problems as in the first case.

While our anatomy is generally the same, the details (proportions, sizes, sensitivity, etc) differ. Just think of male genitals. Growers vs showers, big "static" vs small "jumping around" balls, tight skin vs loose skin, thick skin vs thin skin, etc. The general recommendation is to listen to your own body. If your balls are squeezed and it hurts - use clothes with a bigger pouch. Pain in the scrotum, lower back, and in the area below the kidneys can be related to over-arousing. Masturbation can perfectly heal this issue 😉

Experiment 😉

I must be somewhere in the middle.
A Med latex is too tight, digs in and creates rash lines.
The next size, Large, falls off or slides down.
Then there is the rolling problem I have with latex or rubber.
The latex that sits at my waist rolls up into what looks like rope. I like rope, but not latex rope. Then there is the sweat issue.

I'm still looking for latex that works for me. These are some of the reasons why I haven't bought more latex.

you should try with thinner latex - preferably 0.25mm. 0.4mm can be a bit too thick when it comes to private parts, while the thinner gauge is both very stretchy and comfortable

If your balls are squeezed and it hurts - use clothes with a bigger pouch.

Thanks for the clarification and your explanation. My underwear seems to be the same size as my regular underwear so I don't know if that's the problem. I've used tight denim shorts, yoga pants (for women) before and never cause me pain, just the latex, I know denim and spandex are different to the latex but even when I'm standing up sometimes it hurts. I'll try to bought with bigger pouch or bigger size the next time to try because the sensation feels great.

Pain in the scrotum, lower back, and in the area below the kidneys can be related to over-arousing. Masturbation can perfectly heal this issue

Well even after masturbation it still happens, so I'll keep looking, thanks Like Ra.

you should try with thinner latex - preferably 0.25mm. 0.4mm can be a bit too thick when it comes to private parts, while the thinner gauge is both very stretchy and comfortable

Thanks for the advice, the only shop I have available does not specify the thick measurement but the next time I'll try to change with better quality and thinner latex.