How to motivate your team if nothing is going as per your plans and strategies?

do a brainstorming  session, when they get involved they will think about outlets

meeting outside the company's with a delicious meal and a joint interview between everyone and to reach common ideas and points

I am sure you heard this "When going gets tough , the tough gets going". 

First step would be doing analysis why Plan A has failed and if Plan B is ready , make changes in strategies because they were not effective to motivate the team.

I guess best way to motivate a team is to conduct a group activity and show some insipirational stuff it can be anything which everyone will agree with .

 

easy that is means i'm not good

The only way to get out of a negative mind set, specially when things dont work, is to think positive and talk positive. This means discussing about right plan of actions, top performers, great team work, setting smaller milestones and applauding top team players.

It is a tough task, but I suggest

Transparent analysis of the plans to identify the defects and taking corrective actions.

Firstly, accept & make them accept the fact too. Secondly, don't rush to criticise, humiliate or abuse anyone. Thirdly, don't pin-point out individuals in public but rather talk to each one accordingly in private to sort out things. Fourthly, constantly give encouraging & motivating statements to them for instance; defeat is a temporary condition, giving up or quiting is what makes it permanent. Professionally & positively arouse their attituteds & spirit. Make them feel important & that they are still or will still be part of you. Give them life & success stories or lessons- givie them something to live up to or live for.