What may be actual cause please help.

Long ago i had back pain and in last june i had testicle pain too for which i took the treatment as doctor suggested me that it was infection still i had some pain so i did the ultrasound which was also normal and then after that it reduced but still i had sensation down there so doctor told me its because i am taking too much tension after that also i have sensations till now too and in this february i did my hiv and vdrl test too they were also negative i did that because i read some online articles and got frightened about it last month i started having lower abdomen pain and after that few days penis pain too started so i again got frightened and visited to 2 doctors and have talked to 2 doctors on practo too they all told me there is no problem its just that i am worrying too much and told me to neglect that I am ready to do but still i have some sensations  in penis and testicle sometimes in a day which just happen for few seconds they do not cause much problem but make me tensed