Hi,I had my hair straightened from wella but applied mehendi after 4-5 days.i am facing hair fall at

I will explain why. You can not, ever, ever, ever(am I clear?), use any straightner with a henna based product, ever!!! mehendi aka henna is the worst for hair color. The metals are fairly unstable and when henna is produced the strength of the product is very inconsistant. You need to use a conditioning mask asap. Apply what ever mask you buy, put a cap on to keep the heat in. Then for a few minutes blow dry with the cap on. Let it sit for about a half hour and rinse with cool water. Do not shampoo your hair for about a week. It may sound gross but it dries your hair which you do not want to do. Use conditioner to wash your hair only. Also, try going to the salon for service next time. If you can not afford to get it done professionally you can look for a salon that does classes and they will do your hair for free as part of their class. Edit or add a comment in your question with your location and I will let you know where you can do this, where ever you are.