Nether Portal spawned me in Lava/New Portal Formed in Nether upon 2nd entry

First time to build a portal in this world. I stepping in and there seemed to be lag, tried to step out after 30 seconds or so and that was when the "generating terrain" screen came on, when I was in the nether I was falling and then burned in lava sadly losing my fortune III diamond pickaxe.

Upon reentry to the Nether a second portal was formed at a 90 degree angle from the first and there was no nearby fall into a pool of lava.