Can I be happy in my life if I do not follow God¹s plan for me?

If you do not follow the vocation for which God made you, you can attain a certain degree of happiness in this world, and still attain salvation (go to heaven).

But you can never be as happy as you might have been, had you followed your proper vocation. This is why it is so important that you discern correctly.

The discernment of your vocation is likely to be the most important decision you will make in your entire life! Of course, there are trials and tribulations in every vocation. To become a priest does not take away all suffering. But there is great joy in laying down one's life for Jesus!