Move your focus to the sole of your right foot. Tune in to any sensations you feel in that part of your body and imagine each breath flowing from the sole of your foot. After one or two minutes, move your focus to your right ankle and repeat. Move to your calf, knee, thigh, hip, and then repeat the sequence for your left leg. From there, move up the torso, through the lower back and abdomen, the upper back and chest, and the shoulders. Pay close attention to any area of the body that causes you pain or discomfort.
From a brainwave entrainment effectiveness perspective, it’s my understanding that the response from isochronic tones stimulation starts to diminish over 30Hz and that 40Hz is about the limit for using them. So from what I’ve read on the topic a 100Hz beat wouldn’t work, probably because it’s too fast for the brain to process and synchronise with it.

Research suggests the negative effects of stress on the body seem to be exaggerated in people who are inactive, a phenomenon called”stress-induced/exercise deficient” phenotype. Because we react to stress by experiencing changes in our neuro-endocrine systems, regular exercise is protective because it regulates various metabolic and psychological processes in the body, including reinforcing our natural circadian rhythms, sleep/wake cycles, moods and blood sugar levels.

Transparent Corp's Research Area is arguably the most comprehensive resource for collated brainwave entrainment research.   Update: the main research area on Transparent Corp's website is currently being updated, so it is offline.  However, you can still access their peer-reviewed research paper as a PDF here: “A Comprehensive Review of the Psychological Effects of Brainwave Entrainment“.
In fact just having a particular range of brainwaves running through our grey matter is also not “meditation”. Brainwaves are not the cause of the meditative state. They are only an indicator that we might be in a meditative state. And then again we might be in some other state as well. Those exact same brainwave frequencies are present during many different activities and states of consciousness, not just during meditation.
When signals of two different frequencies are presented, one to each ear, the brain detects phase differences between these signals. "Under natural circumstances a detected phase difference would provide directional information. The brain processes this anomalous information differently when these phase differences are heard with stereo headphones or speakers. A perceptual integration of the two signals takes place, producing the sensation of a third "beat" frequency. The difference between the signals waxes and wanes as the two different input frequencies mesh in and out of phase. As a result of these constantly increasing and decreasing differences, an amplitude-modulated standing wave -the binaural beat- is heard. The binaural beat is perceived as a fluctuating rhythm at the frequency of the difference between the two auditory inputs. Evidence suggests that the binaural beats are generated in the brainstem's superior olivary nucleus, the first site of contra-lateral integration in the auditory system (Oster, 1973). Studies also suggest that the frequency-following response originates from the inferior colliculus (Smith, Marsh, & Brown, 1975)" (Owens & Atwater, 1995). This activity is conducted to the cortex where it can be recorded by scalp electrodes.  
Several adaptogenic herbs and essential oils have been shown to improve anxiety symptoms by reducing the effects that stress and cortisol have on the body. Adaptogens (including ginseng, ashwagandga, maca, rhodiola, holy basil and cocoa) are a unique class of healing plants that balance, restore and protect the body and make it easier to handle stress by regulating hormones and physiological functions.

That said, I use binaural beats and isochronic tones to help me get over some hurdles, or as a pre-game to meditation. It’s far easier to go deep once my mind is operating on a certain frequency, or at least feels like it. It’s also way easier to get to that point than fighting my thoughts at times. Think of binaural beats and isochronic tones as heavy ammunition that you don’t always need, but is great to have in your arsenal when you really need it.

Both brainwave entrainment and neurofeedback deal with brainwaves, but the similarity stops there. Entrainment pushes your whole brain into a pre-determined state, while neurofeedback teaches you how to move specific parts of your brain on your own. It is the differeence between forcing the brain into a given position, and skills building so you can move it there yourself.