Mechanical Engineering always come with tough jobs, mostly related to field work. You should physically be strong for Mechanical. Career opportunities are in heap but obtaining a good score in academic is also not that easy. It is no doubt the best the field and you can earn a lot of money as compared to technological fields. Computer Engineering is a good field but comes with a verity which you cannot satiate. You can only be a hardware engineer or software engineer. So it is better you should choose mechanical if you wish to switch and in parallel get the knowledge of software or networking.