I say if engineering is something you really think you want to do stick with it! Make sure you reach out to people who can help you and talk with your teachers and let them know areas you may not understand more than likely you are not the only one who feels that way. Another alternative might be to change to a different engineering discipline that might be more aligned with your interest I am not sure what you are doing now. (i.e. Electrical, Industrial, Chemical, Computer, Biomedical, Civil, Environmental etc.)I can remember when I first started my engineering studies I struggle a lot with my studies and I felt like changing my major but I loved what I was working on I chose to stick with it and get the necessary help. What motivates me is to remember why I chose to get this degree in the first place. Some of those reasons are (1) I get to work on some interesting stuff (2) I get to travel and take trips to conferences and plants to see how they operate, (3) I get to help other people learn about engineering, (4) I get to help people with the research I participate in and (5) I get to mentor and talk with students to get them interested and keep them interested in the STEM fields. Again I say if its something you really want there is hope you just may have to work a little harder then everyone else but you will get through. I did and now I am currently working on my PhD. Let me know if you have any other questions.