Hi--Sorry to hear that you're not feeling and sleeping well. I, too, suffer from insomnia at times and sometimes it's hormonally-related.
A couple of questions. Are you exercising/working out? I find if I run any closer to 3 hours before bedtime, I often will wake up between 2 and 4 a.m. and can't fall back to sleep. I, too, am in the perimenopausal time. Could you be exercising too close to bedtime?
Also, when do you take your Atenolol? Sometimes people do better if they take it at night as opposed to in the morning.
Have you talked with your doctor (cardiologist) about your anxiety and insomnia?
I don't want to scare you and this probably doesn't pertain to you, but sometimes women have anxiety and insomnia when their hearts are acting up.
Good luck
Atenolol, is an beta blocker? Is insomnia listed as a side effect, anxiety?
I hate to suggest more medications, but given you get such good results controlling tachy you may want to try a prescription sleep aid (pill) to see if it can help you adjust to atenolol, i.e., take the sleep aid only as needed and for only a short time (don't have any estimates on length of time, a few weeks may be enough). What about anxiety, are you sure it is related to your mediation? Here again, there are meds to help deal with Anxiety, and maybe they too can be taken for a short time, not for the rest of life.