Help.. I just want a serious advice

Hello, good evening. I just want to ask what should I do?

Earlier, I confronted my mom about her going out and not coming back for a day (we suspect she's cheating).

She's been doing this for 3 yrs or more maybe, but we only got to know it last year or last last year. 2019 maybe?

We confronted her about it soooo many times. At first she told us who, where, why (but it's a lie), then she gets mad, or cries that she's happy there and it's only for 1 day (coz she doesn't go home for a whole day and she does that for like 3 to 4 times in a month).

My dad goes away for work every 6 months and only stays for 3 months with us. But he calls us everyday that it's so hard

So I confronted her about it earlier and kept her from leaving, she got mad and says do I want her to die- out of nowhere. Like why would u die????

P.s I'm already crying while talking to her coz it made me feel so hurt that I told her it's becoming hard on me that she's doing this to us and dad but ya know shes just mad and shouting and stomping.

And she still left..

Idk what to do anymore tbh, u know, I pour out my feelings just to get brushed off. I've been keeping it to myself for months, everyday I wake up just to check if she's still in here, I think it's becoming a habit and a trauma to me.

Anyways, I feel a little bit better at saying all those things to her but she responded if I wanted her to die. Wow