If you want this middle part separated then you may try to use no top nor bottom facers.. or add appropriate control edges.. also you have a lot of subdivision at the upper part fro no particular reason yet while there are missing some for the transition.
for the “bulbs” you may subdivide it later and use special selected rings while using proportional editing (sphere or inveres square) with individual origisn as pivot point.
If modeling is difficult, you can also connect shapes. (Use the same vertex for the contact)
To create good modeling, the process of manual revision is essential.