Your main security problem with using obsolete software (OS and Apps) is that as new exploits are discovered, they are no longer being patched, which means that your computer remains exploitable forever.
Doesn't matter what protective programs you install (and as time goes on, more and more of them will also not be updated) you will never have a "secure" machine.
Now if you're an especially cautious user of the Internet, then you may be lucky, and go quite some time without contracting an infection, but it will only be luck that keeps you clean, and do you really want to rely on good fortune for your security ???
You may not like W10, and there are many that feel as you do about it, but you cannot forever hold onto an old OS, just because it feels familiar to you, and you don't like change. At some point you're just going to have to bite the bullet, and upgrade to an OS that's supported.
Dan has recommended Mint Cinammon to you, and if you choose to try it out, I think you'll be surprised by how easy it is to use.
I have a friend who was like you, and about 12 months ago he was unwilling to move from W7. So what I did was put Mint Cinammon on a USB drive, so that he could "try it out". All Linux distros allow you to do this, so that you can see whether you like them or not, before you install them on your hard drive.
Once my friend had got used to using Mint via USB, I installed Mint on his hard drive, but set it up to dual-boot alongside W7 (this is easier to do than you might imagine), so that he could use Linux when he wanted to go online, but retain W7 for offline use (with all his familiar Apps).