Can't cope with the fear of death.

Hi everyone. My name's Chris and I'm 24 years old. I'm new here and thought about posting here for a while but I'm hoping for a solution/help to my current problem. And probably this will be like a exhaust valve for all the stress I've got. Not sure how to start, I'm not a man of words tbh.

Anyway, 2 months ago I decided to get the tattoo I've always wanted - a phoenix which rises from the ashes - which I believe fits my life pretty well due to a couple of painful events in my life. I always made the out of my situations. Unfortunately, for some reason I had a mental breakdown due to it's dark colour and size (probably felt like I'm not good enough to have it on my arm and shoulder). I thought about getting it removed instantly but decided to get used to it instead. During this time (which took about 1 1/2 months) I thought about how long it takes for the technology to get that far so I can remove the tattoo without any scars. Then I realized I'll be 30 years old in 5 years. Then I'll be 40. 50. 60. 70. 80. Death. I've been so scared to get older and die. I can't image what it's like to be dead. I don't want to die but it's inevitable. This triggered my depression. Now I cannot stop thinking about it. Even though I believe in God my brain constantly tells me "What if you are mistaken? You don't know, you just believe. And you can't understand this nothingness and this life - from the start to the end." This drives me crazy. I'm rarely hungry, I don't know the meaning of life which creates so many questions in my head. I wanted to be a father someday but now I feel like I'd sentence my child to death by giving him/her life. I feel like I'm trapped inside those thoughts and need to burst out. Most of the time I feel like I got a lump in my throat which leads to a sick feeling. This whole situation seems so unreal, like a bad dream and I'm trying to wake up. I'm scared my girlfriend will leave me someday even though we agreed to work on our relationship and ourselves and support each other. Just how can I beat my anxiety and go on with my life? This robs so much power from me, but my hope is still high. Though I have no idea in what direction I should head to. Maybe there's someone around here who got some helpful hints to cope with all of this. And maybe this might help someone else as well which I'm hoping for.

Cheers. Hopefully I didn't bore you guys :)