Welcome to the forum, you will find all sorts of opinions of how to manage your diabetes but the important thing is to find a way which is enjoyable and sustainable and really becomes a new way of eating not a short term quick fix.
Some find alow carbohydrate approach works for them but that can vary between the Keto approach of very few carb to others who will regard low carb as being no more than 130g per day but often it will be around 100g per day. Yet other people find a low calorie or shakes-based regime to give them a kick start which they then follow up with keeping a watchful eye on carb intake. It can depend on what your HbA1C is, if you have weight to lose and if you have been prescribed medication as to what might be suitable.
This link may help you with some ideas.
https://lowcarbfreshwell.co.uk/
With an HbA1C of 55mmol/mol it should be very possible to reduce by dietary changes, often GPs will give people the opportunity before prescribing medication as it is not the magic bullet people imagine and people still need to reduce their carb intake, all carbs not just the usual cakes, biscuits, sugary drinks. Caffeine does affect blood glucose in some people but that is very individual, it is the cumulative effect of the milk and sugar, if you have it.