Thank you for contacting JustAnswer.
I am sorry to hear about the problems you are experiencing in your relationship. While it can be understandable for sexual interest to wax and wane a bit over time, the absence of physical intimacy seems to have evolved into a constant in the relationship. It is possible that your boyfriend may be experiencing sexual side effects from his antidepressant medication, many of which can cause decreased interest in sex as well as other sexual side effects. It could be helpful to discuss this possibility with him so that he might be able to see if his doctor may be able to offer another medication that may not contribute to such problems. Some of the newer medications are not a problem in this way.
Please let me know if I can help further.