Dylan_43 :
Honestly I like the way your mate thinks, I'll give a LTE modem a try thanks, price really doesnt matter when its this slow.
Go to your mobile providers and see what they have for you.
Be careful though: some of those sales people have no idea what they're talking about and may be perfectly happy to sell you a really bad solution. The last thing you want is to end up on a 24 month contract for something that's worse than your tethered phone and - pay attention here - this is entirely possible with lots of retail "modems".
Do you have a modern and high-end phone? The modems in high end phones are often better than many (even most) consumer grade LTE modems. Have a look into my #2 question above. Can you get better from your phone already?
If not and you're ready to spend some money, make sure you get to talk to someone who actually knows what they're talking about. At the point-of-sale you have the power because you can walk out of their store at any time and take your money with you. It's much, much harder to get good support once they've taken your signature and your money. I'd be asking for some sort of cooling off period or minimum performance level before parting with my money (particularly if you're signing up to a new contract). It's possible, for example, that the tower itself is at capacity, and even with the latest modem sitting right next to the tower, you'd get terrible throughput because the tower itself is servicing too many devices. The solution there would be to try a different provider - but you can't do that if you're locked in to a 24 month contract.
The mate I was talking about explained his situation and got passed up through support levels before spending his money. Finally he got through to a guy who told him the specific LTE frequency on the tower his house was connecting to, sent him a link to a pair of antennas and extension cables, and could explain to him exactly how far apart and in which orientation to mount them... and why. That guy knew what he was talking about and my mate was sufficiently convinced at that point to part with his money.
You really shouldn't need such an elaborate solution, but the point I'm making is to try and be sure you have some guarantee or assurance that the proposed solution will work, and that the person you're speaking with has sufficient expertise to actually address your problem
before you give them your money. It's unlikely (not impossible - but unlikely) that the "tech" person on duty in your local store will be much help.