You have said that you have tightness when pulling back erect. This implies that you do not have tightness when pulling back not erect in which case you have a tight foreskin opening which needs stretching.
Also the statement that you have difficulty retracting fully over the corona (the back part of the glans).
With a tight frænulum - which you no doubt do have as well - the foreskin will pull back behind the glans, but "bunches" up there.
Please note - use "Preview" to check what you have written and how it will appear before you "Respond", and because this forum is moderated, you will not then see your submission until the moderator has a chance to confirm it.