Trying to add stuff to 2 separate tattoos in an attempt to unify it and make you feel better about it is probably not gonna help.
Once you add, you can't take away. If you hate it afterwards, the only solution left would be a HUGE coverup.
Sometimes, tattoos just take some time to grow on you. If it doesn't, you can also try to link the tattoos together in your mind by assigning some form of significance to the combination.
Elsewise, do some research, work with an artist and find a design that can incorporate both tattoos and which you can live with.
If all else fails, do what @oboogie said and just drown them in a sea of tattoos.
