Don't slow the fan down ever, could fry your Mac.
Trouble is everything runs off Kernal_task.
You can save us asking dozens of questions by submitting a report from this App for us to look at…
EtreCheck is a FREE simple little diagnostic tool to display the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to help people help you with your Mac. It will not display any personal info.
https://www.etrecheck.com/
Pastebin is a good place to paste the whole report if you capture the URL while there…
https://pastebin.com/
Whew, they've changed pastebin & made it harder, but after pasting in, click Create new paste button, then Embed button, then copy the URL...
<script src="https://pastebin.com/embed_js/KuvnghqA"></script>
The relevant part would be like...
https://pastebin.com/embed_js/KuvnghqA
Don't use these, they are just examples, yours will appear different.
Workable but harder for me to work with...the Note tool on the bottom of this editor's toolbar, as shown in the image, to copy and paste the output from EtreCheck. In a Reply before you click post, look for this to add longer texts...