Firstly, I'm so sorry you are suffering so much... It really feels like the pits and that there is no way out, but with care and time things will start to ease up.
Can you take neurofen? I find this helps to take the edge off, and it's non constipating.
Are you using any type of stool softener? I was using lactulose for ages, but have recently switched to movicol, and I find this is much better at keeping bms consistently soft. You must drink plenty when taking any type of softener or fibre supplement to keep things soft.
A nice relaxing warm bath after a bm is good for relaxing and soothing for pain. Have as many as you can a day.. Some on the board have sitz baths, but I just soak in the tub.
Before a bm put a blob of Vaseline on your anus. It just helps to lubricate things and makes the first wipe glide and not pull. Then use wet wipes or wet cotton wool/tissue to clean up.
Try to take it easy.. One day at a time.. Be kind to yourself and try and stay positive.
OMB x