A much needed upgrade

Hello, I am in desperate need of a new computer! The computer I'm using now is over 10 years old, and neither I nor my girlfriend make enough money combined to overtake our bills enough to save money to buy new parts for a computer with any amount of speed! My computer is starting to fail and has been for the last few years, but I haven't had the courage to ask for help because I didn't want to ask for money. I hate that I even have to do it now, but things have gotten worse!

Here's what's going on so far:

Of the 5 Sata ports only 1 still works!
Despite my best efforts (I have my A+ Certification so I know my way around computers) It seems to be slowing down significantly.
Programs are taking longer to open, Files seem to go missing, sometimes my Antivirus decides to just close itself despite multiple successful scans while it's working and fully updated showing me NO viruses, or spyware!
Also the Onboard sound doesn't work, so I had to get a Sound card and it's VERY snug up against my video cards fan!

the long and short of it is... it's a mess! My computer is falling apart basically, and I need a new one ASAP!

So I'm asking my friends for help. If you can spare a bit of money to help me out and buying the parts to build myself a new computer I would be VERY VERY grateful! I'm not asking my family because they don't understand the need to have a decently working computer in this age. As long as it turns on and even halfway does what it's supposed to do then it's not broke... well... yeah, it is! That's why I need your help! Any donation is appreciated! Thank you for your time!