The reason for this question is short answer.
1. weight. It's too heavy for your body to bear now. Although it can be lifted, it is not only ineffective, but also easy to get hurt.
Suggestion: lose weight to 30-35, and change to 40KG after completing 4-6 groups of movements. Get help, break out.
2. Heart and lungs. This problem, both thin and fat people should exercise. Only when your heart and lungs are strong can you gain weight and keep breathing!
Suggestion: keep running 1-2 hours every day, and cooperate with rhythmic breathing when exercising!