Thanks for sharing your experiences. I used to be that way. Negative thinking - it's a habit. I broke it with work. 'Work' because negative thoughts are like weeds in the soil of our mind.. they pop up often & without our effort. God's will is positive thoughts~ they're like annual flowers - it takes sowing, weeding out, diligence and perseverance... (and avoiding current click-bait, news media - their job is "if it dies, slanders, gossips or bleeds ..it leads").
Take this or leave it - I’d say (actually Jesus said, below) you’ll do best by filling your mind and meditating on things true, noble, reputable, authentic, compelling, gracious—the best, not the worst... Jesus said (Philippians 4: 8 ) -
Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things.