The first time I played My Time at Portia, I had the same issue, and it felt like it took ages and ages to do the bridge. It was much easier on subsequent playthroughs. Basically what I did was build about 6 furnaces to get the crafting going early on, and always had at least 2 of each subsequent crafting station (more as space and resources allowed, although there were a few that just one was sufficient for. Making sure you get a crafting commission every day really helps as well, because that's your main source of income, which makes it easier to afford more land, inventory upgrades, etc. Fishing is also ridiculously lucrative once you get good at it.

What my Portia daily routine normally looks like is something like this:

• Wake up, check mail (if any).

• Grab resources that have crafted overnight (if any).

• Go to town hall and pick a commission, looking for something that I have most or all of the materials to craft. The plan is to get it made and delivered that day if possible, so if there's a choice of something that doesn't pay well but can be done immediately or something that pays better but will take 2-3 days to make happen, I pick the low paying one.

• Check map to see if any locals have quests that day. If they do, go and get the quests.

• Go home and craft the commission item, plus any items required by other quests picked up that day. If any crafting stations have finished production, set them going again.

• Deliver crafted item to recipient(s).

• Gather resources for the rest of the day. I usually pick one activity and stick to it, say mining, fishing, hunting (the sound of dying colourful llamas makes me sad, but I want their pelts), etc.

• Check crafting stations when stamina has run out. Set more crafting going if needed.

• Go to bed.

The other thing is that the big "main" quests for building those major projects aren't necessarily meant to be done quickly, as they're the bigger story events that gate your progress through the game. Once I stopped trying to get them done as quickly as possible, and let myself get sidetracked on other stuff, I enjoyed the game a lot more. I spent quite a lot of time just spending whole days on, say, just mining, or harvesting wood, or fishing, while ignoring the bridge entirely. (I actually think I spent about two weeks fishing once. I got really, really into it. It then took me another week to sell them all.) By the time I thought "oh yeah, I should do that bridge thing", I had more than enough of all the resources needed, and then it felt really quick to do. I ignored quite a lot of main quests for a really long time, including one that narratively I should have done much quicker. Let's just say that

Speaking purely from my own experience, the mistake I made with My Time at Portia the first time I played it was I was too focused on being goal-oriented by following the main quest. But the game's not really about that. I had a much better time when I slowed down, focused less on the main quest, and more on crafting stuff for the locals (so many stone stools) and selling them preposterous amounts of fish.