Kudos to you for making the change!
Anyway, you mentioned that you are using only Fudge Sea Spray and Quicksand to do up your hair. FSS is meant for volumizing purposes while Quicksand can be treated as a form of styling product to be used. With the combination of these 2, you will definitely get a matte texture finish. GD will be able to add a touch of slight shine to these 2 that you are using. It will then look more textured with a bit of shine and not to mention, shine is especially important for people with coloured hair. In any case, GD is definitely going to improve the outlook as a whole.
However, we ought to understand that GD is heavy as a tradeoff. So, to put it simply, GD isn't really the solution to your problem of collapsing hair. This problem isn't uncommon in our local context as the high level of humidity just makes it worse.
The main element that is lacking from your hair regimen is the use of a hair spray. Hair spray is used to fundamentally hold and fix the hair shape there. With no hair spray and with reference to the picture that you hope to achieve, there is no way that your hair can withstand right here in SG. I shan't be commenting on the holding factor for FSS. Give PowerPoint hair spray a try. It should be able to hold it there well enough through the day for you.