Hey Geoffry!
Given that your GAD test was positive, you are probably LADA or Type 1.5 and will progress to Type 1 within a couple of years. You will need insulin. In the initial stages, they usually try oral meds - I don't know why! As insulin is inevitable and can actually help to preserve the remaining pancreatic beta cells, I would have thought it would be better to begin insulin straight away. Anyway, that's not what they do. I went onto insulin within the year and it was the best thing I ever did. It's not a breeze, and it has it's down sides, but for me, it was the best course of action. The trouble with LADA is that you tend to peak pretty high after food and tend to be very sensitive to carb. Make sure you test after meals and if your BG starts to rise, get onto insulin. In the meantime, it will be the Gliclazide that is causing your hypos rather than the Metformin. Glic makes your pancreas produce more insulin - it will only work for a short time, because eventually, your pancreas won't be capable of producing insulin. The metformin makes your cells more receptive to insulin, but will only lower your BGs by a point or so.
You don't need to take too much carb to correct a mild hypo. 1 or 2 jelly babies will do it. They have about 6g carb each and work pretty quickly. LADAs are generally pretty sensitive to carb and the advice to take 10g quick acting followed by 15g slow acting carb sends my BGs really high. So I don't do it! Try a jelly baby and test 15 minutes later to see what effect it's had. You'll soon get the hang of it. Keep testing until your BG is steady.
Keep asking questions. There are several of us LADAs on the forum at various stages of the condition, so ther is usually someone around to help. We don't have our own area, but the Type 2 area has people on the same meds as you and the Type 1 area has people with autoimmune forms of diabetes, although mostly insulin users. Have a read of both because they are both really usefull to LADAs!
Take care
Smidge