OP - this sounds a pretty exhausting situation for both of you. Has it always been like this (you forgetting major things/him lecturing/demanding apologies) or is this something that has developed over time?
Either way, its clearly not a positive dynamic for either of you and your relationship - and lectures and apologies are clearly not fixing the problem, and can only breed resentment on both sides.
There is some good advice on this thread about seeing what you can simplify and cut out of your daily routine/share out tasks better so you are able to prioritize sleep and you health, and simple things like checklists that could help you with routine and tasks now but the situation is likely more complex and needs a comprehensive approach.
Your days sound exhausting - and its certainly possible that lack of sleep and epilepsy medicine could be contributing. I would also ask about your weight and whether you snore - as medical issues like obstructive sleep apnoea can develop over time and affect your sleep quality, memory and focus. You also dont mention your age but that could also be a factor in hormonal and medical issues. The idea of a GP visit and health check sounds a good one - medical review, some blood tests to check hormone/vitamin/iron levels and discuss the possibility of other issues.
Lifestyle changes - stopping any alcohol and prioritising more sleep would be helpful. Do you get any time to yourself, do any hobbies or exercise apart from the dog walking? When do you get time with the DCs and how do you spend it?
How about work? - you describe it as stressful, full time work. Only you know if burnout is a possibility but- are you being supported there? are you taking tasks from work/mental stress/emotions home with you? is there any way of adjusting your work load, dropping or delegating certain tasks or roles to others or even taking a sabbatical/role change. Would you be supported by work if you needed time off for health/stress reasons?
I think I would try and have a discussion with DH, proactively, not in response to an issue/apology situation and explain that you are actually quite worried about these lapses and why they are happening - and that you need to pull together on this. Dont get into the emotions side yet - (eg 'you make me feel x/you act like my boss/its ruining our relationship) and dont let it slide into blame/lecturing on his side - just keep focused on 'I know I am having problems with this and want to tackle it, and to do so I need your help, it may require adjusting our daily routine'.
If hes not listening or willing to help, or is actively encouraging/enjoying the dynamic of apologies - then you have another problem but it at least puts the issue out on the table and shows you are seriously in dealing with it.
Really hope things get better for you