Alternatives include hot lemon and honey drinks, or ice lollies. Steamy rooms also help. If you only have a few eeks to go you can use lavender essential oli which helps to fight the infection and also helps you to sleep..
I think for coughs the advice is much the same. The only other thing would be something like Olbas Oil used in a vapouriser but I don't know if that is safe for pregnancy, you'd need to check with a pharmacist. Even things like cough sweets are often not allowed. Why not ask your midwife? They often have lots of info. And treatment like reflexology might be safe.
I got some cough medicine from a pharmacist in the States, and showed it to my Doctor here yesterday, who said it was OK to take, but to try and minimise how much I took. It's one that doesn't contain alcohol. Was trying to avoid it, but have been coughing so much that I've been vomiting (lovely), and couldn't stand it anymore. Have just looked on the internet, and most sites advise not taking anything (including throat drops, which Dr also said was OK). Now I'm having an attack of the bad mummy guilts. .
On the up side, the cough has calmed down, so will avoid the cough medicine from now on.
You could have tonsilitis. Maybe you need antibiotics. If you can, have a look with a torch to see if you have white spots on your tonsils - if so go to the doc. I know how you feel about wanting to use natural remedies, I feel the same but I did need antibiotics when pg with dd1 and at the end of the day you need to be well.