Strepsils is fine if you're not taking the purple one which is Strepsils max or something like that. The ones that're honey lemon flavour and all those are fine.
You can also get anti-inflammatory pills called Danzen. Avoid taking off the counter cough mixtures as they may contain alcohol which is unsafe for breastfeeding.
In any case, I would still recommend that you see a doctor to get the proper meds than self-medicating. Remember to tell the doctor that you're breastfeeding so that he won't prescribe antibiotics.
The others like resting more, drinking more water would help you recover faster.