No wonder you're grumpy with all that head banging.
Had the OP been told the house was being sold and not offered a contract thd new owners would very easy be able to end the tenancy.
Agreed, assuming the new owners were landlords not residential owners you can't just 'end' a tenancy though, they would have to give notice (of whatever is stated in the agreement).
The oP was given a fixed term agreement and this has a secure tenancy for a year. The new owners couldn't kick her out.
The new owners wouldn't have been able to buy the property with a tenant in situ, without specialist conveyancing or a buy to let mortgage, which they obviously wouldn't have applied for because they cost more, you need more deposit and they are a family who want to live there, so it's a bit of a moot point, it would never have gotten that far.
Besides that, the contract contained a 'break clause' as the OP has mentioned that above, it's normally 6 months in and tenant and landlord can then give notice to leave. I assume that is what the landlord was planning, it takes a good 3 months to complete on a house purchase plus extra time to sell it, so that was probably why he got them to sign, so he had 6 months guaranteed rent.
However the oP was no longer able to afford the rent and that's now "bad landlord".
Can't it be both? Greedy landlord and unfortunate tenant, I'm sure the tenant would rather have stayed in the house and not have cancer, she has stated that that is the reason for the move.
I'm actually wondering, given that tenant default insurance isn't part of standard landlord insurance (it's an added extra), whether he had her sign a new contract JUST so he could claim off the insurance for loss of rent for the full 6/12 months anyway.
The reason he's being pegged as a bad landlord, at least by me, is that he's been paid by his insurance for the loss of rent, due to unforseen circumstances (the situation here is EXACTLY what you pay that for, tenants falling on hard times) and he's STILL pursuing the tenant.. even though he's already been paid out and she doesn't owe anything now. I still think he's committing insurance fraud by trying to reclaim the money from her.. I wonder if he'll give it back to the insurance company??
I can't feel sorry for the landlord, he's not out of pocket, he's not had any drama, he's got his house back clean and tidy and now sold, the only added thing he's had to do is put a claim into his insurance, who have paid, best case scenario for him to be fair.
I do however feel for the OP, she's got cancer, her world's falling to bits and she's got this shit now hanging over her head.