advice please..

so this morning I found out I'm 4 weeks pregnant . my emotions are all over the place right now . I have a 1yr old and a almost 3yr old and a would have been 4yr old that past away shortly after birth , I told my boyfriend this morning and he insisted on getting a abortion and said the decision is up to me . I feel like I'm stuck in a hard place I love this child already and don't know if I will be able to handle a abortion and losing another child. I'm just really lost right now