Keep at it. Thats the only real advise their is. That and don't bet everything on it. Take care of family first. I got lucky. I almost ended up back doing 12 hour swingshift as Power Plant Operator. High dollar but no life. I just found 2 back to back perfect positions for this kind of thing and had spent most of my life in and out of industrial operations and have a LOT of overlap in my degrees. Took like a decade to get enough skillsets and training to land this.
As far as sound goes, wait till its needed. Use place holder on all cast till its near the end. Then choose what sort of genre (or multiple genres) fit. Then I honestly think either go for a pro group that does this like Hyper Duck or something or possibly go for a net person like 331 e-rock or someone from the OG Remix list of sound engineers to join you. Voice acting to a minimal IMO if you are on budget. Hit sounds work fine for many situations. It worked back in the day so if the game is good and you are low on cash then go that route and possibly dive into crowdfunding for that part of it because VA is expensive. If you can choose a design that allows you to work within your limitations easily. If there isn't a theme yet you might try looking into some sort of loose theme that would make sense to go low VA with.
By the way Cintiq is nice, but Intuos 4 works too. If this is your first time into the pool know that a good tablet helps but the difference between Cintiq results and Intuos results IMO is largely just the artist's experience. Cintiq is closer to real life paper, but I've used both that sort of thing and Intuous and once you learn to draw without watching your hands (couple of days) on an Intuos the extra cost doesn't really mean much IMO. To each their own but its a bit overkill if you ask me.
We should swap stories as the months roll on. We'll probably each be hitting roadblocks as we pass milestones left and right and since we both went with Unity we may have useful stories to swap. I'm going the route of modding [Universal Fighting Engine in Unity since my C# is limited for now. If you haven't seen it
there is some real potential for you to shortcut some stuff if it meets your needs.