The total stock market hit a record high 14 months ago. You almost certainly would have thought it didn't "seem like a deal" then too, yet it sure looks like one in retrospect, now that it's 25% higher. You don't know what it's going to do in the future (if you did, you wouldn't be asking us), but it's likely to go up over the long term, and since your investing horizon is for the long term, don't worry too much about the current price (unless you're about to become an active trader). Even if you invest $15k at the absolute market peak, and it doesn't return to that level for 30 years, that particular $15k isn't going to have a significant effect on your future.
Fidelity's Spartan total stock market fund is just as good as Vanguard's, so no need to do Vanguard-through-Fidelity if you don't want to.
"paralyzed with indecision" and "not going to pretend to be a seasoned investor" seem a bit at odds with "invested in PHK for the dividends", which seems like a rather intentional move by someone who knows what they want. It's probably good to hold some bonds in your overall portfolio, to make you feel better when the stock market goes down, but I don't think holding them "for the dividends" (really, "interest") is the right reason. And if they're held outside of a retirement account, it would be better (for tax reasons) to hold them in your Roth and hold stock funds in your taxable account.
