My drawing was pretty crappy when I started ID. It’s not so much about being the best sketcher in the room as much as it is about being able to communicate your thoughts both verbally and visually. Having strong understanding of your users, coworkers, clients, manufacturers, and being able to successfully communicate with them is probably one of the most important skills to have. By the way, having computer engineering skills is always a plus in the industry. Having your specialty is good; while you may not become the best sketcher, you should find your expertise in something. Sketching is a matter of practicing a lot.
Great sketching resources:
How to Draw - Scott Robertson
Design Sketching - Klara Sjölén
idsketching.com - Spencer Nugent