@Grumpy Porridge, given your issues as discussed in previous threads I think you would be in a very good position to push for a freestyle libre on the NHS. This would take the stress out of testing for one.
Different people do different things.
Some people don't carb count at all, but memorise a repertoir of meals that work for them with specific insulin amounts.
When I was diagnosed aged 8, there was no blood testing available, and insulin protocols were to take a couple of insulin injections per day and eat fixed carb quantities at fixed times. So I memorised the "blue book of carbohydrate values of proprietary foods" and got very good at carb counting (much easier for an 8 year old than a 28 year old). And my T1 mother already knew how to carb count so her cooking was pre counted.
At twenty I was introduced to a glucometer and a basal/bolus regime and that changed my life. Though my control has been on and off over the years I had a rough background guestimation of carbs and could eat on a basis of this sort of meal needs this amount of carbs. But it's easy to slip into bad carb counting habits - I'd swear apples had less carbs when I was a child
. Sometimes I weigh stuff just to see if my guestimates are roughly right.
But I now self fund a cgm so I have the advantage that if my levels start to spike more than I expect after a meal I can pop an extra couple of units. But it's not for the faint hearted (I have to be careful of the implications of stacking insulin when taking more insulin even though the first lot hasn't run out) and would be extremely risky for someone not using a cgm.
You've got to remember that you are still in the early stages of T1 and it'll take time for you to learn how to predict how your body reacts to insulin. (And that will change over the years).
So as to whether it's OK just to guess insulin amounts rather than carb counting, it depends how your guessing is informed. If you guess that tuna with green salad is going to need the same carbs as chilli with a big pile of rice, then you're going to be in trouble. If your guesses are advised by an underlying knowledge of how many carbs in the two meals, then you could be fine. But carb counting is the science behind dosing for meals, and the reason why insulin amounts can be judged so as to keep your levels in that golden in between range (not too low, hypos are just miserable, and not too high, that causes long term damage and also makes you feel bad).
It's great that you've got your mum cooking for you, but is she counting the carbs for her meals as well?
Good luck.