Hi, I am currently an undergrad in physics/astronomy in my senior year. I am interested in doing work of a theoretical (or semi-theoretical) nature in the future. My reasoning for this is that it seems it does not require a lot of resources other than access to data and I think I would enjoy it. However my grades are not very good. I have had a very hard time as an undergrad. I also have no work experience. I am kind of a "shy person" so I haven't approached anyone to ask about this, and it also took me some time to come to this conclusion decisively. :) I know it is necessary to get a PHD in order to have a good understanding of the current research fields of physics but at this point I am worried I won't be able to get into grad school... Can anyone give me some suggestions of steps I can take to go in the right direction?