Doing an SMC reset probably will not fix this, but it likely will not hurt and it takes only moments to do.
One thing you might try - seeing as yelling has not worked either - if your MacBook is one of those with an easily removeable battery, shut down, remove the battery, connect to your power adapter and restart. Some batteries, particularly older ones, have been known to expand and interfere with the keyboard and trackpad.
If that is the case, replace the battery.
Best of luck.