I'm sorry you are in this situation OP. I've TTC 10yrs, 3 losses and no cause for sub-fertility found. Al my losses were due to different genetic issues due to older eggs though. Last year, the consultant said that due to my age now (early 40's) had I considered a donor egg. No, until then, I hadn't even thought about it.
I did some reading, but we haven't proceeded any further. My limited understanding is that IVF might be covered via NHS if you meet the criteria for IVF in your area. Some have a max BMI, some only accept non-smokers and others either don't provide any NHS IVF at all or have other restrictions.
A donor egg in the UK apparently provides more info about the donor than abroad. The child can also ask to find the donor when they are 18. There are UK sites which will tell you, height, hair colour, skin colour, ethnicity, education etc about someone.
When looking abroad, countries have their own rules and the donor isn't always traceable to the child in later life if they want to find out more. I think Spain was an example of this I looked into. Some countries, women are paid, so that is a consideration as to WHY they are donating their eggs! With such little info about the donor women I'd read about other issues/worries. You might choose a donor from say Spain, but that donor might actually be ethically Japanese, Nigerian, Russian etc, so you may have no indication of physical characteristics the child might have.
I'm sure there will be others with actual 1st hand experience, but this is the limited info I've found so far. Best of luck OP 