I would be really wary of snacks like that seven. To be honest a lot of the dietary advice given at hospitals isn't very good, and sometimes applies more to other types of diabetes than to gestational diabetes, which can be a bit weird. For snacks I mainly eat things like:
Veg sticks and hummus
Olives and feta
Cheese
Nuts
Granny Smith apples with peanut butter
Cold meats
Very small amounts of dark chocolate, paired with nuts.
No added sugar jelly pots.
I had a big sweet tooth as well, and I found the best thing to do really was to try and do without as much as possible. The initial sugar withdrawal was a bit grim, but it didn't last long. It's not forever, you can have these things after the baby is born (although I am keen to modify my diet as much as possible afterwards, to hopefully minimise the risk of type 2 as much as I can).
Broadly speaking I have found that the best thing to do is to go with a low-ish carb, high fat and protein approach. Some carbs with every meal, but brown complex ones, and not massive amounts. I've swapped to Burgen soya and linseed bread, brown rice, wholemeal pasta, etc. I've been very lucky, as I have remained able to tolerate most carbohydrates. Some women find that they are fine with , say, brown rice, but get terrible readings from pasta, or potatoes. It's trial and error really.
As for the high fat: as an overweight person I have struggled a bit to get my head around eating tonnes of cheese, and sauces made with double cream. However, it works. My consultant has said that my post meal levels are really, really well controlled: I am on insulin now for my fasting levels, which are harder to do anything about. My overall average glucose level is now "basically normal".
I also have put on very little weight: at almost 38 weeks I weigh 3lb more than I did at booking in. This is at no detriment to baby, who is showing as average size on growth scans and is healthy and well.