Help Can't download apps, says memory needed

[loveallpandas]

For a while, I was using the default browser for my phone and a message popped up saying my phone was infected and I had to download a specific antivirus that they showed the link for. I didn't have a good antivirus(guilty) and I remember going to play store and trying to download a popular antivirus(not the one they showed). Then, Playstore tells me that I didn't have enough space(17 gb wasn't enough I suppose) so I deleted my YouTube and Instagram. Guess what? The system message came right back. I thought it was my Playstore that somehow got infected. So I deleted it and downloaded an apk file for it. (This all happened a few months back so my memory is pretty foggy cause I was on my other phone for a while so anything after this, I am not 100% sure) I guess it installed pretty ok cause now I have 360 Security. Recently, I forgot all about this, and I checked on my phone again and realised that I didn't have Chrome. I tried downloading it and the old message came back and I accidentally deleted my YouTube Instagram and Facebook and the message kept coming back. So it tried the apk file for it but now I can't seem to install it cause the system keeps showing that I don't have enough storage space, which is hilariously untrue. I have no idea what to do. Someone smart out there, please help.