Disabled US Veteran needs a new PC rig

Hello there, thanks for dropping in to see what this is all about. Let me take a moment to introduce myself.

My name is Matthew, online I'm known as Paroxsym or simply "Oxy". I'm a 32 year old U.S. Army veteran with a service connected disability that prevents me from working most jobs that I'm qualified for. Both of my knees are completely trashed and require replacing, but I live alone and have no transportation means to make this a viable option. Over the last couple years I've turned to videogaming and livestreaming to make ends meet, and  its gone decently well for the most part. While my bills get paid, it leaves very little left over for things like food. Even less so to replace faulty PC parts, which is what I'm faced with right now.

Recently I experienced a power surge here that killed the power supply that was in my PC and unfortunately damaged the motherboard on my PC as well. I'm currently using an old power supply from a build I did in 2010. While the PC still runs as is currently, it destroyed the built-in network card on the motherboard (I've got a super inexpensive replacement NIC in one of the expansion slots right now) which is somewhat inconvenient, but it also seems to have caused a more significant casualty, my graphics card. Again, it still runs but the card is becoming increasingly temperamental and unstable, requiring an underclock to run in a stable manner. The card is old enough that its also well outside warranty, as is the rest of the machine. Its clear that its about to die entirely, and needs replacing.

This is where I turn to you. I need help. I cannot afford to rebuild this PC on my own, yet I need to do so in order for me to continue paying my bills. The amount that I set as the goal is enough for me to build a PC that will perform well enough for me to continue my livestreaming for a good few years without requiring any upgrades whatsoever without being overly ridiculous (also includes a bit of arithmetic to account for this site's transaction fees, etc).

Thank you for taking the time to read this, and any support is appreciated, no matter how big or small. Even just sharing this around might help me get things back on track.