My OCD is very bad currently and I can not take it anymore. I start taking medications but soon their effects stop.

Recently, my OCD is worse than usual. I was on medications for a long time but I stopped them as they were getting ineffective and because my family and even doctor is concerned about weight gain 100 kgs at 5 ft 11. I fear my car will get stolen and check that doors are locked 1000 times. I have started fearing that vehicles behind are somehow "out to get me". I don't have any hallucinations or delusions but I feel like I can mostly read people's behaviour and people are always pissed off at me.