Well, you have come to the right place as we have all been there. 3 lines is hardly 'going on'.
I myself was first diagnosed just 3 months ago and faced all the same apprehension that I'm sure you are facing right now, not to mention all the unhelpful advice from others less familiar with the condition.
I was somewhat lucky in that my other half offered me tremendous support, to the extent that together we were able step back and take a good look as to where we were. It was rapidly concluded that we had probably a fairly unhealthy lifestyle as far as our diets were concerned and the recent holiday photos clearly showed that we were both a bit over weight.
Almost overnight, we both changed our diets, he was quite happy to eat the same things that I did. In fact we found it comparatively simple to adapt the diet to my needs. Gone were all the convenience foods, loaded with those dreaded carbs and in were fresh cooked items with plenty of fresh veg and perhaps a small potato or a small portion of pasta. Since I like cooking this isn't a problem to me.
I note that you are Type 2 diet only just like myself. What your profile doesn't convey is how serious your diabetes is, though diet only would suggest not very.
If it makes you feel any better, My BG was all over the shop for the first 3 or 4 weeks as I was avoiding sugar like the plague, but had been advised by my Diabetic Nurse (DN) (as I'm sure you have) to eat plenty of starchy foods like potatoes, rice and pasta. Like many others who arrive here, I had not made the connection between carbohydrate and sugar. Within a week or so of learning this somewhat important point, I had my BG not only within the 4-8 mmol/l limits placed by my DN, but actually within a mmol of that prized target of 6.0. OK, so I have an occasional excursion to over 7 but what the hell.
The rather good bit is that over the 2 months that it has taken me to get the diet exactly right, I have lost a stone and a half in weight and as a result, I look and feel a lot better for it. Fortunately, I have now stabilised the weight and for the first time in many years, I am no longer over weight - just!
What you haven't said is if you have been given a Blood Glucose meter and a prescription for those all important test strips. If you have then control is in the palm your hand. If you haven't and you can't persuade you GP to prescribe the test strips, then it may pay you to buy the test strips youself, at least until you find out what food works and what doesn't (it's your health we are talking about here which has no price). Almost any manufacturer of meter will send you one free gratis (or buy one - they aren't expensive), but the strips are a rather expensive (around £25 for 50). As a diabetic you don't have to pay the VAT on either the meter or the test strips but be prepared to argue. There are some bargains to be had on the internet or even direct from the manufacturers.
This forum is for you to air your worries and questions. You will find a huge amount of sympathy and support here, as we are all in the same boat. Give it a month or two and, hopefully, you will have a completely different outlook. Who knows you may be typing a response like this to someone else who is feeling a bit down having just been diagnosed as diabetic (and maybe a less rambling one).
I would say, 'good luck', but it isn't down to luck. It's about grasping the nettle and taking control.
IanS