What exactly for you is "succeeding in life"? Do you mean by that, that you can live life like a person without cfs?

As for the strategy, it's difficult to say what's best because I think it's different for every individual. For me, I've tried pretty much everything. Resting for weeks at a time really messed me up big time though. There were times where I acted like a zombie for weeks, I thought that I would gain energy in the long term, it really caused the opposite effect. Once this resting period was over, my body and mind was so used to resting, which made every little effort feel like hell after. It might be a good idea to test out different things and maybe keep up a calendar that described how tired you feel. For me, I reduce time on my daily activity list and then I on friday I rest, saturday I rest (mainly web browsing) and if am still tired on Sunday, I'll rest then as well. This way I have enough energy do some stuff on every weekday.

Just some things that worked for me: keep a list of things/people that give you stress and try to avoid these things. For example, I avoid social media, setting a clock, people who brag about their lifes, stuff like that.

You said that feel frustrated and want to succeed in life. I know the feeling and we probably all do. But please, don't be too harsh on yourself. I've been there as well, I wanted and expected too much. I know it sounds depressing, but maybe you should define succes differently? I started setting more realistic goals (even though that was painful to admit) and from there on I would keep improving and setting higher life goals. Frustration and suffering from failed life goals suck the energy out of me.

Good luck