Wi-Fi/Hotspot antenna not working at all

I have dropped my phone a few times no significant damage done to the phone until about 3 days later I noticed the adhesive that holds the back of the phone on was separating on both sides and noticed that my phone won't connect to home/public Wi-Fi or let me use my hotspot. I search for network but absolutely NO networks can be found at all. I still have 5g phone service and my Bluetooth is 100% functioning properly. I believe the Wi-Fi antenna has shifted from the falls or possibly dirt could've gotten into the gap where the adhesive has separated or could very well be damaged completely. I took my phone into a fix it place and they told me that I would have to replace the motherboard and it's impossible to repair just the Wi-Fi antenna only costing me $797! They never actually inspected my phone to begin with to confirm if infact it was my Wi-Fi antenna or something else. I believe it can be fixed and I shouldn't have to spend so much money and replace the motherboard for that 1 thing. I'm confident I can do the repairing myself if I knew the proper steps and diagram of the procedure and have the proper tools that's needed of course. Hopefully this can be done with least amount of money spent. Could someone please help me figure this out please?

Thank you in advance, very much appreciated!