I have recently been charged ault to injury domestic (Scotland)?

cirstances are as follows: Were out for an evening with my partner. On way home we went for a food takeaway. I asked him to carry one of the bags as i was carrying three. He refused i left him with one of the bags containg his food which he kicked across road. I walked away and he caught up and asked for chips out the other bag which i handed to him. He then proceeded to throw this bag across the road. I again walked on. Suddenly i felt a slight thump to my head i turned round to see what hit me and was pushed to the ground by my partner. He ran across road i chased after him and grabbed him and asked what the hell he was playing at. He told me to let him him go I did and walked on again back across road he followed me and pushed me to the ground again. I grabbed him again and told him to piss off and stop pushing me. Again he screamed at me to let him go which i did only to be pushed to the ground again from behind. I retaliated by punching him once and baked off he charged/ grabbed at me again. I punhed him again 2 - 3 times. He then phoned for police and ambulance. I walked on again, back to flat. Shortly after i was detained by the police and questioned. I admitted to punching him and explained the cirstances. Because i only had a few nasty cuts/grazes to the hands from being pushed to the ground while he had a small cut at side of eye and some bad bruising to face I was charged with ault. Solicitor has made a plea of self defence. However i understand this can be quite tricky to proove due "minumum force". I am concerned what can i expect if found gulilty under the cirstances. So far as i know there are no independant witnessses. I dont as of yet know what he has said. Only indication from police is both stories fairly simular. I do have photos of cuts on hands to proove i was pushed to ground.