Thank you for reaching out to us.
You seem to be a good student as you have a good score in your 10th and 12th. I can understand how frustrating it can be when you are not where you wanted to be, rather in a worse situation. And indeed, the frustration can also affect our future scores. But dear, we cannot control everything in the world and sometimes we have to accept things that don't completely match our desires. This again, you did quite well by remaining committed to finish engineering although you were not very keen. A part of a good life is formed from making thoughtful decisions and then living with that decision, whatever be the result. And accepting things that we can't change happily!
We cannot do much about the external world and the things there. But we can always act with the things that are in our control. So act with whatever is in your control and then let it go. Nothing goes waste dear, We get an experience and some learning that will help us in our future.
Now your engineering is over, let's plan ahead. Past is gone, and we can only take the learning from the past to improve our future. If you are still interested in technology, probably you could prepare for further Mtech. Or maybe you could choose to start working. In current times, companies are not very much interested in your marks and it is only important for the first opportunity. After that, it mostly depends on how you have performed at the job and what you have learned there.
There are many jobs that are overlap of computer with mechanical or electronics. Maybe you could explore those opportunities or would you now be interested in something different? Maybe you can try for something different. Or probably get a short term course and then try for some opportunities. It will take some time but things will get better for sure. Few of the most renowned people of the world were dropped outs or failures. Very few have been from the premium institutes. They didn't care about from where they were studying. They had the aptitude, and a passion to do something using that aptitude.
So, now gear up for the future challenges with full motivation. Decide about what you want to do and leave no stone unturned to do that. A few things have been shared in the above answer. If you need further help at any point of time, get in touch with anyone here. You are now an engineering graduate and you can now take action as you want to - to further move ahead in the direction you want to!