I’m in this exact same situation right now and have been for the past 18 months. Long covid (fatigue and pain) and spent as much time at home as I have in work. Here is what I have learnt:
-Do not go back to work until you feel much better, it will set you back and you’ll get sicker. Make sure you have an occupational health review at least once before you return. Check if CFS is covered under the Equality Act or not; you might be able to ask for reasonable adjustments.
-Don’t feel guilt for not being there. Your health is far more important.
-If you can do without working and that income, it is better not to work and focus on rehabilitating.
-Be aware that if you resign you might find it more tricky to claim benefits. However, if you can show your job has/would make you more sick this might be considered a good enough reason resigning. See citizens advice pages for details.
-The worst case scenario is that you use up all sick pay and/or be processed under sickness management rules for your organisation, which could ultimately result in being dismissed on grounds of ill health. Check your employer’s policy.
-This doesn’t necessarily mean you’ll find it difficult to find employment afterwards especially if you have recovered and your next job is more suitable for your health needs. The same could apply if you’ve taken a break.
-When you run out of full sick pay entitlement and you go onto half pay, make sure you are paid statutory sick pay as well which could be allowed for a long term health condition. That’s all I know but look into it.
-If you’re on half pay+ SSP you will likely be better off than if you were claiming benefits.
-Something else to consider: you could do temping or contract work even if it’s part time to build up a better sickness record.
-Depending on the type of job you do, if you in demand companies might take you on anyway if you state that the previous/current job is not conducive to your health.
Chronic fatigue is about pacing. I cannot emphasise how important it is not to push yourself. If you do you will relapse and go back to square one. Some rethinking about priorities is needed, if you can afford to.