Hello Sonal,
First of all don't be sad. You said you are a hard working student and ready to work for your goal. So, whether to take admission straight away or appear once again for CAT it's a little difficult choice to make like that only without calculating all pros and cons related to it. Also, you mentioned that right now you are pursuing M.VOC in BSI can you elabroate it for me, so that I can help you out in more precised way.

Still it doesn't matter whether you are weak or strong in maths. Practice can make you efficient in scoring good marks. All you need is riight direction in your practice. Also, CAT is not the only option for mba, there are options like CMAT, XAT, MAT NMAT, SNAP and many more. If you really wanna pursue mba degree.
MBA is a course were initially investment is quite high but without thinking about ROI and not getting what actually you should be getting then such a investment is futile.
Maths is not only section of the paper. there are other sections namely; Verbal Ability & Reading Comprehension and Data Interpretation & Logical Reasoning almost in all the papers.

I will sugeest you if you are really wanna do it, then take a weeks time and  sort out your resources according to syllabus and previous papers and plan things in small packages and then try to complete them and work on your schedule for it. This will help you in letting know what all your weak and strong areas are. And after a week if you feel you can do it, then don't hesitate a bit and go for it. Aim all the mba entrance exam and practice for them. You can take help of a good coaching where you live or correspondence course and do not forget to utilise youtube, it is one of best resource available at your foot steps. And if not then find a good college and take admission in it.

I hope this lessen your problem little and still have any doubt or problem feel free to comment it. I'll help you in all possible way.

All the best!!