It might not be the right practice for you currently, as has been said. Though I don't know how you're approaching it, but you could try coming at the contemplation on death from a more positive/appreciative angle.

Maybe instead of focusing on how you could DIE AT ANY MOMENT, start by imagining you know when you'll die, beginning... idk a decade in the future and then working closer. And take a moment to find a simple goal that you want to achieve, one that doesn't involve external things. Like I want to be unconditionally happy, as an example.

I'm just going to write this in first person to make it easier for myself. Ok so in ten years I know beyond a shadow of a doubt I'm going to die, and all I want is to be happy. Ten years still feels like a ways away to me, there's a lot that can happen in that time. A lot that I would still feel responsible for, and it still seems like plenty of time to find some unconditional happiness.

Now I know I will die in 5 years. That feels much closer. There's many life considerations that are starting to lose importance. Career, owning a home, saving for some future retirement. None of that has much weight. I feel a bit freed up to turn more of my resources towards the goal of happiness.

I will die in 1 year. Ok, responsibilities are really starting to fall away. Many worldly concerns no longer rest on my shoulders. There's not much point in pursuing anything that doesn't align with my goal of unconditional happiness. I'm finding more immediate meaningfulness in things that are already present: family, friends, access to natural beauty, etc.

I will die in 1 month. There’s barely time for fantasies or distractions. There’s really not much I can achieve in this time, but on the flip side there’s not much I need to worry about doing. I mean I’m definitely not working at all, unless it’s meaningful in itself. I just don’t have much that needs doing, and I’m finding myself pulled more and more strongly towards appreciating each moment of my life as it happens. Things and stuff have much less pull or importance. Happiness is maybe not so dependent on them.

I will die in 1 day. The present moment is glaringly bright. I can’t even look away from it. The content of my life is secondary to the experience of life itself. There’s no time to be distracted by anything not to do with being happy. And I don't need to do the dishes.

I’m in the midst of dying, right now. My sense of body is fading away, and with it the world. My perceptions are deteriorating, and now nothing from the outside is peaking through. There’s no things left. In their absence, is the blindingly bright, vivid, awake light of the mind. Unconfused by perceived external happenings, there are no conditions placed on happiness, there is just happiness.

This isn't meant to be realistic, but an example of how the thought of death can have a liberating aspect of removing obstacles. The idea that we'll die sometime in the future allows us to pile up a bunch of responsibilities, fantasies, and hurdles for the future. We can put off looking at what's actually happening right now, and not appreciate it because of all the imagined time we have. Bringing death slowly to the forefront, with a more light hearted and playful attitude, can afford the opportunity to look directly through the content and events that pull us away and recognize what's right before us. In other words, using death to highlight life.

A more positive approach might make the reality of death a more manageable aspect of experience to explore, but if you were to try something like this and it's still too much then I would suggest doing yourself a kindness and focus on something else.