@Lisek I am in agreement with @Shaz51, our loved ones that have insight are often acutely aware of the burden they are and reminding them of this is not helpful. Just as we cannot be responsible to how they react to things, placing the responsibility of our own emotional responses on them is another load that is really not theirs to carry and it can further weigh them down.
Realising that we cannot love our partners back to mental health is at first hard to swallow but can then become liberating as we focus on what we can do - providing a loving and supportive environment which leads to better outcomes. Encouraging them to get the level of professional support they need along with healthy lifestyle choices (management is far more than meds).
Learning how to maintain our own mental health by employing strategies that foster resilience to reduce carer stress and burnout (the term for this is self care) is ever so important and having our own counselor is often so helpful; they can help us with coping methods and psych education. This helps reduce "expressed emotion" that is the unhealthy responses to our loved ones disorders. They can also help us with "boundaries", that is relationship rules that protect our hearts.
In times of crisis, such as when our loved ones are suicidal, we do need to help them more and get them to a pdoc or hospital, whilst a GP can be helpful, these are times when specialist intervention is needed. When depressed, our loved ones are not good historians and other symptoms they have had are not passed on and can lead to a correct diagnosis not being made; carer collaboration is necessary. Things like has your partner had times when they have spent too much money, had bizarre thoughts, thought they were someone extra special or have super powers? Have they spoken too quickly, had trouble staying on topic, change topic? Letting docs know response to previous medications is also helpful. (I have done a chart up).
I personally believe we can libe well in spite of a diagnosis. I have found that by letting Mr Darcy know that I am on his team, supporting and advocating for him, reducing expressed emotion, having realistic expectations and being practical about things, life is a lot better. Mr D still struggles daily, there is "living grief", but there are many silver linings and I chose to focus on those.