I did a quick search and would highly recommend you study logs of top warlocks. I don't play demo this patch myself but at a 5minute peak it looks like your opener is inconsistent and frankly, sloppy.
For instance I looked over your eggnog kill compared to a top warlock. You're popping Tyrant after only 1 hand of guldan and no demon bolt. He's casting tyrant after 2 demon bolts and 2 hands of guldan. Yes he has tier, but he's also stacking on-use trinket with tyrant, you aren't.
(Yes I believe he's also pre-casting demon bolt, hard to confirm, take my advice with a grain of salt)
Source for visual comparison.
https://www.warcraftlogs.com/reports...&view=timeline
vs
https://www.warcraftlogs.com/reports...&view=timeline
Yes he out gears you, but there's a reason his opener is more than 4x your dps, it all comes down to rotational precision. The opener (15-30 seconds) is probably the best place to practice.
I would also recommend you not use any addon rotation helpers. It sounds harsh but if you react to an addon's stimuli, your dps will not get good and the game starts to play you.
Be the best warlock you can be!