The Eight of Pentacles represents your past mental health situation. The number 8 is associated with wealth, abundance and well-being, so it is likely that you have already achieved a good level of mental health in the past. The card can also indicate that you have already taken steps to improve your mental health, such as following an exercise regimen or changing your eating habits.
The reversed King of Pentacles indicates that you are currently experiencing a period of low energy and fatigue which could negatively affect your mental health. The card also suggests that you may have lost control over your emotions, which can negatively impact your mental health, especially if you don't take the necessary steps.
The reversed Queen of Pentacles can show that there may be some difficulties in your future when it comes to looking after your mental health. The card also indicates that you may encounter some obstacles and feel stuck in some areas of your life. However, that doesn't necessarily mean you won't be able to handle your mental issues.
In conclusion, the tarot cards suggest that meditation or yoga practice could be a good way to improve your mental health both in the present and in the future. While you may face some difficulties, these practices can help you overcome them and bring balance to your life. Therefore, meditation seems to be the most appropriate choice for you right now.