Eight months for track and a yard throat is completely normal, honestly. Track work eats time for everyone because you keep finding the one point that derails the odd wagon and you can't move on until it's fixed. The layouts you see ballasted and grassed within months are usually ones where someone decided to live with the rough spots and regret it later. You're not slow, you're just at the part where mistakes are expensive to undo later.

On the ballast question, I ballast in sections and only after I've run stock over that section for a few sessions. My rule is simple: no glue goes down until I've had a good few running evenings with zero stalls, no shorts, and no point motor adjustments on that stretch. Once the ballast is set with diluted PVA, pulling a point motor or nudging a set of points means digging it out and it's miserable. Doing it section by section also gives you that visible progress you're after, because each finished chunk of ballasted track looks so much better than bare cork that it feels like real movement even though it's only a foot at a time. I worked in order from the yard throat outward, since that's the bit I was least likely to change.

For the shed exit, the trick is to keep plain, straight, level track running well past the portal before anything changes. If the portal is the first thing after a point or a curve, a stall right there is hidden and you can't see it to fix it. Give yourself a good run of straight ballasted track either side of the opening, wide enough of the portal to clear your longest stock's overhang without clipping the brickwork, then test with your longest coach and a long wheelbase loco before you fix the building down. Cut the opening generously too. It looks fine if the portal is slightly larger than the train needs, but looks awful if a coach kisses the brickwork every pass. Keep testing as you ballast each section and you'll catch any wiring gremlin while it's still easy to reach.

I dragged my feet on ballasting for ages because the wetting step kept piling the stuff against the sleepers. What fixed it for me was a cheap bottle of isopropyl alcohol and an old dropper. One drop of that on the dry ballast first and the diluted PVA just wicks right through instead of beading. Went from a job I dreaded to knocking off a foot of siding in an evening. As for the shed, I left way more room around the opening than looked right on the plan, and honestly once the building has weathering and a bit of clutter round the mouth you stop noticing the extra clearance.

A trick from the old days: leave the last six inches or so either side of the fiddly end unglued. Scatter the ballast dry so it looks done but nothing's set. Then when you finally get in there with the soldering iron you can just hoover it off and start again. I learned that one after chipping set ballast off a crossing with a screwdriver one winter, never again. Also, take photos every month from the same spot. Bare board to ballasted track doesn't feel like much day to day, but put four photos side by side and you'll see you're miles further on than you think.

Cardboard first for the shed. Cut a rough mockup of the building out of cereal box card, tape it down, and run your longest loco through it for a few evenings before you commit to anything in wood. I did that on my branch line terminus and it caught two problems: my 0-6-0 tank nicks the portal edging if I take the curve too wide, and the unoh I'd planned blocked the viewing angle anyway. Cost me nothing to move it on paper.

Also on the timeline thing, my last layout took a solid five months before a single blob of scenery went down, and that was with me working on it most weekends. Some of us just run long on the fiddly stage.

Update: tried the dropper trick on the loop and it actualy worked, the glue went thru the ballast instead of pooling like before. Question though, I left the last stretch near the fiddly end dry like someone suggested, but the loose stuff keeps shifting when I test locos. Do you just re-sprinkle it after each running session or does it settle down eventually? Cardboard shed mockup is cut out and waiting for the weekend.