Howdy from South Carolina, and welcome to the forum.
The Shield is a stiff sprung gun, especially when new, though it does loosen up with use. When my husband first had me try it, I couldn't rack the slide. Then he taught me a different technique, to hold it closer to my body, arms against chest, and then I could rack it.
The magazine spring is probably responsible for a large percentage of Maglula Uplula sales. I highly recommend this loader if you plan to shoot any pistol enough to be proficient.
A good cleaning and lube does help a little with slide resistance. Mil-Comm TW-25B, is a lube that "slicks" friction points well.
I don't have the .380 you mention, but my .380, the Sig P238, is the lightest slide spring I've ever used.
Good luck.