Welcome! As E.T.O. said, you have found the right place...and believe me, nothing is too embarrassing to share with us. I am self-dilating! That should be the ultimate in 'embarrassing', but I do not in the least feel that.
Firstly, you did not create the fissure; they just happen. What can get them going, however, is 'holding on to get home' though my hubby does that all the time and has no problem! They can be exacerbated by stress, and it is very important to learn how not to stress. I have the ease to to say that, as I am a homebody, but I still can stress. I am learning to relax my internal sphincter, the one that is supposed to be involuntary, but it is working. I just relax, and talk to myself about it!
Do take the time to read what is here, and do a search on the forum for what you cannot find, or ask any questions you have.
By the way, there is nothing wrong with checking your rectum, but do you mean checking inside, or just your anus? I gently massage the outside of my A with a bit of petroleum jelly (of everything I have tried, this has proved the lasting one), and find that relaxes the muscle too. Took ages for me to even 'touch' down there...so silly.
Anyway, glad to found us!