How rare is it that I have "foundblocks 1" on my antminer d3??
I've been running it since the start of December on my 19.3 gh/s d3? It makes me wonder if I should have just solo mined because I would have just earned 1.9 Dash coins instead of what I have now (less than .41 dash)

Check
https://www.coinwarz.com/calculators/dash-mining-calculator/ (put in your miner hashrate, current network difficulty and see "Days to generate one block mining solo")
I've tried out of curiosity and result was 266 days to find block ( using 19.3 Gh/s)
BUT
You need to understand this is pure average value
so it's possible you can find 2 blocks within that period (and during next 266 days you won't find any)
or you could find 0 blocks during that period and then find 2 blocks during next 266 days period
or if very unlucky you won't find any blocks for 798 days (3*266) and then can find 3 blocks in a row.
etc. etc.