The good news is you do not need to buy a new tv, ; however some adjustments to your existing setup are needed.
I would firstly boost the signal, with a distribution amp, as when you split you effectively halve the strength.
with traditional analogue you could get a watchable pic in these circumstances, but the digital signal is weaker so this is probably no longer sufficient, as it is 'all or nothing' - you either get a clear pic or nowt!
you would then need a small digital set top box for each tv...you can get them for as little as 15 quid, but still...
welcome to the world of digital con! which sadly means having to complicate things and splash out on such things.