HELP!!

My 2 year old has always been a brilliant sleeper but these last few weeks have been dreadful. I have to get her to sleep for her nap and then put her in her cot and bedtime is just horrendous. Bedtime routine has been kept the same but as soon as I leave the room, she cries and climbs out. This continues until she literally can’t breathe she’s crying that much. She’s hysterical. Sometimes wakes in the night crying and won’t go back to sleep in the night to the point I’m that tired she’s comes into bed with us which I have now stopped. Any ideas on what could be happening or what I could do because I’m drained 😭😭😭😭