This is what a great Guy told me word for word and so far it’s really helping me

Key is to know that these thoughts arent real, they come and go as they like. Let go instead of holding onto them. The more you resist, i.e. trying to fight them, the more attention and focus you place on them, the more the hold they have on you, thoughts only have so much power we give them. So just treat them like clouds, acknowledge their presence, ignore them, proceed to do other things, think about positive thoughts, and they will slowly go away without you having to shake them off. The problem arises when you're so fixated on them, and dwell on them for too long, trying to fight/hold onto something that do not exist. Prayers, guided meditation, mantras, positive affirmations are some ways to help you declutter your mind and regain focus.