I would recommend trying out different ones until you find one or more that make you feel at ease & comfortable.
The tone that made you anxious may make someone else feel rested, at ease, relaxed, etc. & vice versa.
Even though we are all the same so to speak (as we are all human) each of us has a very distinct & very different energy signature so what works wonderful for some people won't help others.
I would recommend doing a search on youtube or even better(in my humble opinion) a Sound Therapy
You can customize your own sound waves or use the installed ones.
You can try it free for 7 days to test it out & see if you like it & some sites may offer it or something similar as a giveaway such as the website : http://www.giveawayoftheday.com
You may also want to try doing an internet search for "Free SoftwareAlternative To Natura Sound Therapy" or Free Theta Pure Tones, etc.