Pain at the posterior part of anus.

I am experiencing pain on posterior side of anus, i think somewhat around coccyx region but the main issue is that it is paining when i am pressing a little or if the part gets somehow pressed by clothes but on sitting mainly and it is not paining while lying down or walking/standing and also not paining while sitting unless there is clothes tension or pressing. It is somewhat at the end of anus and i have no history of falling down, etc but yes i do have history of constipation and blood once on 29th jan but it was resolved much since then and i do not strain also since about 3 months while defecating. Another symptom i would like to mention is pain in neck since many years(resolves then starts again sometimes) but since 3 days i am feeling like if some heavy thing is placed on my shoulder so i am using omnigel spray and there is much relief, i just mentioned it as it is somewhere associated with coccyx?