It sounds like you need a bit of a strategy and need to practice executing your countermeasures.
You say people are spamming you. That's fairly vague, but lets stick with example of a wolf spamming smashes. First off, when does he seem to be spamming smashes? Say case 1) he is spamming Dsmash against you when your at high percents. Or case 2) spamming fsmash after only lasering once or twice.
A easy strategy for case 1 is shield way more often than necessary when your at high percents and wait for him to hit your shield with dsmash. Depending upon how quickly you do it, you should be able to drop shield and dash attack him right away. Another strategy (which is harder to master) is spacing yourself to avoid his attack, but close enough that you can punish any whiffs of his Dsmash.
Case 2, once you recognize this pattern, you can once again hold shield, then punish his attempts at fsmashing. Alternatively, you can once again try spacing yourself to avoid situations where you easily get hit by fsmash. Or you can try believing in your ability to spontaneously react to a fsmash by doing whatever to stop it (shield, jab/ftilt before it comes out, DI the first hit to avoid the 2nd).
The main point is that once you recognize something that seems to be giving you troubles, you need to work out a plan of action against it and practice executing it so you do not fall prey to it.
Its a lot more complex than this, but there is no simple thing to write down on how to be better. I feel like with playing smash (or really any major skill your working on), there is a ton of things you simply have to figure out yourself. There will be slumps of "what the hell do I do". It might take you months to ever have some sort of moment where you suddenly seem to be doing better, but it often comes with time. Just keep playing and trying to mix-up your mindset on how you play games to experiment. You should find something that works eventually.