Have you tried soya replacements for meat (like quorn, although if you're still focused on veganism quorn isn't suitable). It contains the same amount of protein as normal meat, and additionally doesn't contain any fat. If you really feel that you can't eat fish or meat, something like tofu or soya might be good. Like you appear to know already, it's important in a vegetarian diet to make sure it's balanced, so looking into taking vitamin supplements or something of the sort may be a good idea.
All the best!