Rather than focusing your attentions on the practical concerns of your life, let your mind wander. Allow your thoughts to come at you in rapid fire succession until you find one that's just concerning and plausible enough that it can consume you for the foreseeable future. Your boyfriend's been acting weird lately, maybe he doesn't love you anymore. That freckle on your hand is kind of weird. Is it possible it's cancer? If something crosses your mind that makes your heart feel like it's being crushed with a ton of rocks while simultaneously floating in a void of nothingness, you'll know you've found the stupid paranoid thought that's right for you. If nothing immediately comes to you, just keep digging. Remember: If you search long enough, you can always find something to dumb stress out about.
Now that you know what it is you're freaking out about, it's time to freak the fuck out. Think about nothing else. Allow the thoughts to fill your mind so fully that they eventually spill out of your brain and into the pit of your stomach. Let your concerns form into a tight little ball that stabs you in the gut and keeps you aware of your stress on a visceral level, even during the brief moments when you manage to distract your brain with other thoughts. Let your baseless concerns take over all areas of your life. When your friends ask you if something's wrong, lie and say you're fine so they don't realize how crazy you are, even though you know that talking about it would probably make you feel a lot better. When you reach the point that your freak out feels like the biggest part of your life then you know you've done it right.
When the stress gets too much to bear, try to remind yourself that you're crazy. Think back on all the times when you freaked out over nothing in the past, and how stupid they all seem in hindsight. Allow yourself to feel okay for a brief moment.
After your momentary break from anxiety, allow your mind to race with all the possible reasons you should go back to worrying. I mean, sure, none of your insane freakouts have ever had any basis in reality before, but who's to say that this time isn't different? What if this one's for real? Alternately repeat steps 3 and 4 until your brain is bogged down with so many layers of thoughts that you genuinely don't know what you believe anymore. Cling to your couch cushion and listen to Netflix in hopes that you can distract yourself long enough to feel okay again.
Now that your freak out is officially of hand, make the decision that you're finally going to confront it head on. Still worried about your boyfriend? Contemplate sitting him down and having a meaningful conversation about your relationship. Does that freckle look like it's gotten bigger? Google dermatologists that can give you a conclusive diagnosis. When you've properly figured out your plan of attack, ignore it instantly. Remember, actually doing something gives your freak out legitimacy, and the only thing worse than shitty paranoid thoughts would be knowing that there's actually some truth to them. Decide that it's best to just keep it bottled up.
Now that you know you won't take any practical steps to help yourself, hunker down and wait for the freak out to pass. Accept it as a part of life and carry it with you as it slowly sinks into the back of your brain. It may take a while, but eventually your concerns will become a thing of the past. This is because you'll eventually find a new, equally stupid concern that will take up all your attentions and you won't have time for the old one. Repeat step 1.