I'm in a similar boat. I spent a lot of time working on my main character and some alts for the guild but without my friends being able to join in. I ended up creating a new character on a different server and was invited to join a guild that has a very large member count who are consistently active. I still do my own thing but sometimes I join in roulette group runs or help lower level members get through dungeons. Sometimes I reach out for help too. I still hop on to my first character to do some quests or whatever to keep the guild alive but spend most of my time with the new character.