Exercise

I’m 7 weeks 2 days. I am a fairly active person, either running, going to the gym or yoga a few times a week. However, since week 5 I am completely drained. Going to the gym before my 12 hour shifts is NOT happening and on my days off the idea of exercise makes me want to die (cue me being dramatic). I managed a 4km jog yesterday but it took me almost 2 hours to even get out the door and the entire run was an emotional battle. So now I just feel guilty all day for not being active. As this is my first pregnancy ever, has anyone found it gets better? Does your energy and commitment to exercise ever prevail?! I’m pretty worried about the weight gain if I don’t move my body because i love to eat lol.