Was suicidal then got better, but messed things up

I [18, F] had slightly severe suicidal thoughts for about a year and really thought I would end my life before this year ended. I finally got help though and reached out to a therapist and told my friends and family and they have been there for me ever since. I even got put on antidepressants, and had a session with my therapist where I was crying profusely and saying every thought of worthlessness I had and how I could've ended my life multiple times to which she told me, "Well, I'm glad you never did it all those times." It wasn't until about a month and a half ago that I gradually stopped having suicidal thoughts and stopped continuing my life as if it would end soon. I'm a freshman in college, so I slacked off severely and didn't care. Now, I'm trying to get my act together and be the 4.0 student I was when I graduated high school, but I'll be lucky enough to make some C's in my classes. I'm just feeling sad now and regret having negative thoughts about myself that affected how I lived my life.