Why is being awoken by an alarm stressful? It never bothered me. In fact I find it more stressful to not have an alarm set due to the fear of being late for work or an appointment. If I wake up before the alarm it's easy to turn off.
Once I realized that, I bought a $30 light alarm. It starts to glow softly about half an hour before my desired wake-up time, and except for once or twice when I was too buried under the covers to see the light, it consistently wakes me much more smoothly and pleasantly than getting jarred awake by a jangling alarm. (It has a back-up audio alarm that plays at your normal wake-up time, which shuts off when you turn off the light part.)
I found off-the-shelf light alarms not bright enough, so I used a bunch of Hue lights to get it brighter:
https://github.com/wpietri/sunrise
I was surprised to discover that the more valuable part was auto-dimming the lights in the evening. I'm much more likely to go to bed on time if there's been a virtual sunset over an extended period. I miss it when I travel.