What would be the best high quality but budget friendly computer for me?

I purchased my first computer in 2017 and I was so excited. It was the 2017 MacBook Pro and has lasted me up until now. I believe it may even have a few more years left in it. However, despite how long it has lasted me, this has honestly been the worst computer I have ever used - 2 USB-C ports and one did not even work after purchasing, I only have on port to use with a charger. Anytime I open a basic app, the entire computer sounds like it may blow up at any second. It is extremely slow, laggy, and the keys only work 2/3 of the time. It has been like this since I can remember, but slowly getting worse overtime. However, it does still operate and I use it for most of my work.

It has a 2.3 GHz Dual-Core Intel Core i5 processor, Intel Iris Plus Graphics 640 1536 MB grpahics, and 8 GB 2133 MHz LPDDR3 memory. I am looking around for a new computer and a friend recommended asking here. I have absolutely no idea what is worth anything or what I would even need.

I do teach so I often have 20 tabs open at once, I do a lot of recording and streaming through OBS, occasionally we will use interactive games on steam. This may go on for a few hours during class time. Needless to say, I do a lot that my computer can barely do/ cannot do at all. I am wanting to send recommendations to my boss at the end of the month to hopefully purchase something around Black Friday.

I am not the biggest apple fan whatsoever, so I do not necessarily need a new Mac. I am not quite sure what I need though. I want to be able to record lectures and lessons without the sound of a rocket taking off the entirety of the time in the background. I would prefer a laptop and something under or around $600 if possible, I do have some wiggle room. What are the best quality and best bang for your buck options?