Recently my dad died

I just feel I need to vent a little. My mind is usually overthinking all the time anyway but recently its been bouncing off the walls and I don't know what else to do.

Recently my dad died very suddenly of a stroke (50 y/o) leaving my mum, my sister and me behind. He was a brilliant man that really kept our family together. My mum and my sister were initially much worse than me and as such I took it upon myself to do whatever I could to keep us together and safe. But now everything seems to be going wrong.

I am doing the estate all on my own and its a lot of hard work with constant set backs which feel like kicks to the balls. For some reason me and my girlfriend are now constantly arguing over tiny issues which never truly get resolved. We were a 1 income family (my dad owned his own business) that was doing pretty well but now someone else is running the business, we have had to make lots of changes and are struggling financially. Work is getting worse and worse because I feel like I am losing my only work friend. I have an exam coming up which I am woefully unprepared for and don't have the free time to revise.

I feel constantly angry, sad, jealous, frustrated, tried, unmotivated. Many years ago I used to self harm and I feel like I want to again but not in the same way. Before it was a release but now I just want some control back. I don't have much free time anymore but whenever I slack and give myself a day off (which is becoming more and more frequent because I just don't want to work on the estate after my job) I don't want to do anything.

I told my girlfriend that I am not okay anymore and she didn't know what to say. My mum has always been pretty suicidal and is now even more so, so I am worried I might lose her.

I am running out of people to talk to because I don't want to become a black hole of depression in someone else's life. I feel like they would either leave me for someone who actually makes them laugh and happy, or they would treat me like a patient instead of a friend and then replace me with someone that makes them laugh and happy.

On top of this, my girlfriend doesn't seem happy living here anymore and says she's bored with life. She wants to do exciting things and book trips which I don't know if I can afford anymore and I don't know if I want to go. I am becoming increasingly paranoid I am losing my friends to other people even though I am not talking to them about how I feel very much.

I recently had my birthday and, while everything royally sucked, I never felt this bad about it all. Its only been the last week or so that I have felt this way.

I got caught self harming before and went through therapy, antidepressants, "write down 5 things you like about yourself" and all that crap. I got the all clear, deemed "cured" and sent on my way. That was years and years ago. I don't want to feel this way but I don't want to go back to therapy or antidepressants. I made a life for myself after that chapter in my life and its all falling apart.