Each time I get to the title screen, it does not show the option to login with Steam, which is problematic since well, that means I either lost everything I've done so far or I cannot access it.
So if anyone has any suggestions, I'd be more than grateful.
I can still log in.
When the Steam login didn't work, restarting Steam or PC usually helped and when it did not, it got fixed on its own eventually anyway (I think?). You can also try searching this or Steam forum if someone had similar problem in the past or try "Verify integrity of game files" for SK in Steam.
As a last resort you can ask support if they can move your Steam account to a regular one. However this is something they don't usually do (I think), so really use it only as a last resort.
Same problem here