Basically mirroring what is said above, 2 years is 4 tests assuming the worse case scenario... However, cancellations aren't uncommon, in reality, you could easily do more than 4 tests in a year, never mind 2 years.
Don't take your theory test too early and you won't need to worry about needing to take it again...
The fact is; driving is a privilege, not a right.
Don't like it? Waste time with public transport and walk.
Or just cycle everywhere.
Private transport may cost more, but time is far more valuable, you can make more money, but you can't make more time.