Honestly, that
is really frustrating, and I totally understand feeling impatient! Feeling stressed like that can make it harder to orgasm though, because it takes you out of the moment. As Sam said, continuing to experiement with different kinds of touch and sensation will help. Try not to put pressure on yourself- people often stumble upon things that work on accident, during their explorations.
As for where you can get condoms- so many places! I’ve looked into it, the good news is that there’s no age limit for getting condoms in England. You can just buy them, of course- online, at pharmacies or stores, or from vending machines in restrooms. But in many places, like sexual health/contraception clinics or some GP offices, you can get them for free.
Here’s an NHS website page that will help you find a clinic if you’d like.
Also, many pharmacies and stores will give you free condoms if you have a C-card. C-card is a scheme that provides free access to condoms and lube. Depending on where you live, you can register for a C-card at a sexual health clinic, with your school nurse, online, at a pharmacy, or a health center. Your card won’t contain any personal information. Places that accept c-cards will have a C-card logo. In some places, C-card services can discretely mail condoms to you as well.
This website should give you the information you need to access C-card.
I hope this helps!