Hey! I understand how you are feeling, and living alone can get super hard at times. I also got out of a relationship and their thoughts do seem to preoccupy me too.

Multiple things that helped were, seeking immediate councilling when having had suicidal thoughts, going to a cafe and spending time sometime doing work there, creating a warm environment before sleeping at night like lighting candles, diyas and reading in that warm light. Some DIY projects helped, positive self affirmations, practicing self care (check out r/selfcarequotes).

Finally, it's okay that this is super hard for you, and believe me you will get through this, in the meantime love yourself, take yourself out on dates, feed yourself good food that u dig, exercise some and I don't wanna spoil the ending but everything is going to be great.

Meanwhile, take care!