Well you don't quite give us enough data, but I'll make some educated guesses (especially about spending and taxes).
At 35, I'd shoot for a 3% SWR if you want to have the option to never have to work again. 4% if you're fine knowing there's a good chance you'll have to make some money in ER.
That means, since you spend, let's say, 4.5k/mo. (job generates 10k net, and you spend "well less than half that"). That means you need a stache of 1.35MM (4% SWR) to 1.8MM (3% SWR).
So you have a ways to go. I'd work on getting those expenses down (54k/yr. seems like a lot). Are you planning on downsizing or moving to a cheaper COL area when you FIRE?
EDIT: I see in the second post you say 3k/mo. expenses, I was just going off the first post's "less than 5k". So in that case you need a stache of 900k (4% SWR) to 1.2MM (3% SWR). /END EDIT
As far as generating a return, there's a few methods people who first hear about ER jump on because they make obvious intuitive sense in generating money (dividends, rental income), but in essence you'll generate money by selling stocks.
In a total return method you build up a big enough stache, and once/yr. (typically) you sell some to generate the living expenses you need. Typically (one hopes) the stache grows more than you sell. While some can't stomach this idea, 95%+ of the time, you'll end up with more than you started, so while it seems you are spending principal, you aren't - you're selling gains (just like spending dividends).
You're doing awesome so far, just a bit to go, possibly cutting some expenses, and some learning. Best of luck!
