Hey! Don't feel like this. Nothing is lost anywhere but you are thinking it from the perspective of depression. So no need to lose your rigor.

Two years of preparation is enough for any exam to crack. UPSC is said to be one of the toughest exam and if your read about this exam then you will find that the average number of students say that 2 years time is enough for the preparation. So if they can do it why you can't crack this SBI exam?

Some of the tips for you:

1. Try learn the Mathematics with great focus. Now a days you can find plenty of lectures on Jobs exams in internet. You can easily follow them and learn.
2. Do study every day. Your sincerity is the most important.
3. Practice mock tests. There are many mock tests available online for free or by subscribing with very low price. Find them out and try to this.
4. Practice as much as you can. Once you get the time management done , you will have a much greater probability than anyone else.
5. Don't get demotivated & study hard.

I hope my answer helps you. Wish you all the best for your future endeavors!

Hey!

1st of all believe that you can do what you need.

being 21 and feeling dumb is the worst scenario, i agree. but that cant decide what you will be in future. so never give up.

starting from scratch or even minus from now is fine. absolutely fine. even without considering your engineering, it is fine.

here is a little advice from me (as a brother), learn some skill. which you think is suitable for you. do some vocational course. have a good knowledge in that. it will take only 2-3 years. then you can work in that field.

or the best thing will be, if you interest in automobile or electronics. go to a mechanic shop or a electronics repair centre. tell them that you are an engineer and you need some hands on experience (leave out all prestige and other stuffs if you need success later). learn some stuff, this will refresh your engineering knowledge. then start a software shop or computer service shop. you can earn enough with pride. or start a mechanic shop. have 2 workers under you. you work too. having a car garage or workshop is not any inferior. you will earn handsome.

at last, if you need only SBI, then apply for banking exams. (they are really easy, not as tough as we think) you will crack in 1st or 2nd attempt. prepare seriously for that. you will see wonders happening in life.

age is not just a number. when it gets higher it gives responsibilities. so start taking it seriously.

if it helps at all. comment me.

Good luck