so, you have known him for 4 years and have been a couple for almost a year, correct?

Has he always been this way or has it slowly gotten worse?

Has he been diagnosed by a doctor as having depression ?

What is he doing anything about his depression? Therapy? Meds? Exercise?

"he suffers from depression so i let a lot of things go..." Are you sure you aren't telling yourself that as a way to rationalize his behavior? Making the depression a scapegoat for his actions?

Furthermore, by blaming everything on the depression, you may be giving him tacit approval ( a free pass ) to keep doing things that hurt you.

If someone repeatedly does not respond to your texts and would rather run errands than be with you , well, that looks more like avoidance than depression to me.

Whatever is going on between you two, you are obviously hurting and i hope it stops soon.