Its just so confusing as to why the antinodes are formed from the constructive interference by superposition of the wave formed by the incident wave and the reflected wave... The phase difference is clearly 180° and not 0°, so shouldn't the reflected wave and incident wave superpose to destructive interference? which would then make it a node.. but not the antinode.. similarly.. with the node.. the phase difference is 0°.. so how come it does not oscillate at that point?.. Honestly, I think how standing waves arise itself is confusing me..
Standing wave animation and see that at a node the phase difference between the two travelling waves is always $180^\circ$ and at an antinode the phase between the two travelling waves is $0^\circ$.