Nursing strike

My son usually breastfeeds and latches well since birth. He’s bottle fed since birth as well. We only use tommie tippie and have had no problems until about 3 days ago. He’s 6 weeks and recently cries at both boobs after about 5 minutes or sometimes refuses all together. and he usually takes both with no problem. He cries so much I have to break down and bottle feed. He sometimes still nurses completely but it’s mostly been refusal. Idk what to do and I feel horrible and like a failure.