Maybe, but you can't really look at all these stages in isolation, as they impact things much later. So getting unstuck via some or other advice one day, does not mean you're not going to get even more stuck later on based on that advice.I do have some much more experienced relatives/friends I can call on if(when) I get stuck.
And the end result should be to have a useable room, not just a room, and to get that useable room with the least disruption and cost.
Looks like you've got the stairs at one end of the loft. Remember that by the time you've got the landing and the stairwell in. plus the protected walls, will you even be able to walk down the side without banging your head on the angled roof? And is the space on the other side of the stairs wasted in the loft? So that leaves dormers, and major structural redesign of the roof.