there is really little that can be done over the internet other than to offer you some advice. i don't know your husband's complete medical history or have any way to medically evaluate his memory issues but he does have some obvious contributory factors: tobacco marijuana use poor nutrition (a guess) insomnia due to unknown factors and perhaps many many other issues. he will need to see a medical professional to start the evaluation process assuming you will be able to convince him to do so. encouraging him to give up tobacco and marijuana may be futile but at least you can try and work on him.
help my husbend cant remimber like he use to. he smokes tobacco and weed he stopped drinking over 4 months ago. and he is losing weight he has a new friend and the guy comes over every day and does not leave till late. then my husband has been real restless at night. he cant even remember where he put his wallet even just after 2 hours. he has adhd that he has had since he was a child and never med treated. other then that he is in good health.