I don't fast on particular days. And I don't do it often, haven't in ages to be honest. But I fast when I want to symbolise I don't rely on anything of the world, kind of to demonstrate that I'm really serious about what I'm about to approach God about, perhaps a friend's illness, or other situation close to my heart. I don't think God needs me to fast, it's more about making a difference in how I approach him, my mindset, and it makes me connecting with God feel more special than usual.

For me though, fasting isn't the big deal it is for many people, because I can go all my sunlight hours without eating anyway. I'm lazy, absent minded, and disorganised, so it's often 4pm by the time I think 'gee, I'm hungry'. For me, symbolically it's a bigger deal to go outside somewhere quiet by myself with my bible, or not speak for a certain period of time.
Kind of like some people do the 40hour famine without their phones or internet - that is more significant and meaningful to them. And God gets my meaning, he knows what is significant to me.

I'm not sure how you would work fasting into your life Hoobs. Perhaps when you need to think about something, redefine who you are and what you want out of life, you could fast to symbolise that this isn't a physical issue, but a deeper one? Not sure.